Implement AString

78 files changed, 1100 insertions, 524 deletions

diff --git a/.travis.yml b/.travis.yml
index f2588ed..02f837e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,6 +32,7 @@ install:
   - sudo apt-get update -qq
   - sudo apt-get install -qq $PACKAGE
   - sudo apt-get install -qq libgtest-dev
+  - make --version
 
 ## Do something before the main test script
 before_script:
diff --git a/src/admin/ladmin.cpp b/src/admin/ladmin.cpp
index d875205..38f0c4b 100644
--- a/src/admin/ladmin.cpp
+++ b/src/admin/ladmin.cpp
@@ -6,7 +6,7 @@
 #include <cassert>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 #include "../strings/vstring.hpp"
@@ -48,7 +48,7 @@ int login_port = 6900;    // Port of login-server
 static
 AccountPass admin_pass = stringish<AccountPass>("admin");    // Administration password
 static
-FString ladmin_log_filename = "log/ladmin.log";
+AString ladmin_log_filename = "log/ladmin.log";
 //-------------------------------------------------------------------------
 //  LIST of COMMANDs that you can type at the prompt:
 //    To use these commands you can only type only the first letters.
@@ -582,7 +582,7 @@ void display_help(ZString param)
     {
         if (command)
             PRINTF("Unknown command [%s] for help. Displaying of all commands.\n",
-                 FString(command));
+                 AString(command));
         PRINTF(" help/?                          -- Display this help\n");
         PRINTF(" help/? [command]                -- Display the help of the command\n");
         PRINTF(" add <account_name> <sex> <password>  -- Create an account with default email\n");
@@ -678,9 +678,9 @@ void addaccount(ZString param, int emailflag)
     if (!e_mail_check(email_))
     {
         PRINTF("Invalid email [%s]. Please input a valid e-mail.\n",
-                FString(email_));
+                AString(email_));
         LADMIN_LOG("Invalid email [%s]. Please input a valid e-mail.\n",
-                FString(email_));
+                AString(email_));
         return;
     }
     AccountEmail email = stringish<AccountEmail>(email_);
@@ -1040,9 +1040,9 @@ void changeemail(ZString param)
     if (!e_mail_check(email_))
     {
         PRINTF("Invalid email [%s]. Please input a valid e-mail.\n",
-                FString(email_));
+                AString(email_));
         LADMIN_LOG("Invalid email [%s]. Please input a valid e-mail.\n",
-                FString(email_));
+                AString(email_));
         return;
     }
     AccountEmail email = stringish<AccountEmail>(email_);
@@ -1773,7 +1773,7 @@ void prompt(void)
         // get command and parameter
         // TODO figure out a better way to do stdio
         static auto cin = make_unique<io::ReadFile>(io::FD::stdin().dup());
-        FString buf;
+        AString buf;
         cin->getline(buf);
 
         Iprintf(SGR_RESET);
@@ -1791,7 +1791,7 @@ void prompt(void)
 
         // extract command name and parameters
         auto space = std::find(buf.begin(), buf.end(), ' ');
-        FString command = buf.xislice_h(space);
+        AString command = buf.xislice_h(space);
         while (*space == ' ')
             ++space;
 
@@ -1809,7 +1809,7 @@ void prompt(void)
         {
             // We don't want passwords in the log - Camel
             if (command == "create" || command == "add" || command == "password") {
-                FString name, email_, password;
+                AString name, email_, password;
                 VString<1> sex_;
 
                 if (qsplit(parameters, &name, &sex_, &email_, &password))
@@ -2218,7 +2218,7 @@ void parse_fromlogin(Session *s)
                             break;
                     }
                     tmpstr += ']';
-                    FString tmpstr_ = FString(tmpstr);
+                    AString tmpstr_ = AString(tmpstr);
                     PRINTF("%s\n", tmpstr_);
                     LADMIN_LOG("%s\n", tmpstr_);
                 }
@@ -2630,7 +2630,7 @@ void parse_fromlogin(Session *s)
                     AccountEmail email = stringish<AccountEmail>(RFIFO_STRING<40>(s, 100));
                     TimeT connect_until_time = static_cast<time_t>(RFIFOL(s, 140));
                     TimeT ban_until_time = static_cast<time_t>(RFIFOL(s, 144));
-                    FString memo = RFIFO_STRING(s, 150, RFIFOW(s, 148));
+                    AString memo = RFIFO_STRING(s, 150, RFIFOW(s, 148));
                     if (account_id == -1)
                     {
                         PRINTF("Unabled to find the account [%s]. Account doesn't exist.\n",
@@ -2812,7 +2812,7 @@ bool admin_confs(XString w1, ZString w2)
         }
         else
         {
-            PRINTF("WARNING: unknown ladmin config key: %s\n", FString(w1));
+            PRINTF("WARNING: unknown ladmin config key: %s\n", AString(w1));
             return false;
         }
     }
diff --git a/src/char/char.cpp b/src/char/char.cpp
index 15ea46b..55dca81 100644
--- a/src/char/char.cpp
+++ b/src/char/char.cpp
@@ -16,7 +16,7 @@
 #include <set>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -74,11 +74,11 @@ IP4Address char_ip;
 static
 int char_port = 6121;
 static
-FString char_txt;
+AString char_txt;
 static
 CharName unknown_char_name = stringish<CharName>("Unknown");
 static
-FString char_log_filename = "log/char.log";
+AString char_log_filename = "log/char.log";
 //Added for lan support
 static
 IP4Address lan_map_ip = IP4_LOCALHOST;
@@ -140,9 +140,9 @@ std::vector<GM_Account> gm_accounts;
 
 // online players by [Yor]
 static
-FString online_txt_filename = "online.txt";
+AString online_txt_filename = "online.txt";
 static
-FString online_html_filename = "online.html";
+AString online_html_filename = "online.html";
 static
 int online_sorting_option = 0; // sorting option to display online players in online files
 static
@@ -232,7 +232,7 @@ Session *& server_for_m(const mmo_charstatus *mcs)
 // Function to create the character line (for save)
 //-------------------------------------------------
 static
-FString mmo_char_tostr(struct mmo_charstatus *p)
+AString mmo_char_tostr(struct mmo_charstatus *p)
 {
     // on multi-map server, sometimes it's posssible that last_point become void. (reason???) We check that to not lost character at restart.
     if (!p->last_point.map_)
@@ -333,7 +333,7 @@ FString mmo_char_tostr(struct mmo_charstatus *p)
                     p->global_reg[i].value);
     str_p += '\t';
 
-    return FString(str_p);
+    return AString(str_p);
 }
 
 static
@@ -470,7 +470,7 @@ int mmo_char_init(void)
     }
 
     int line_count = 0;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         line_count++;
@@ -528,7 +528,7 @@ void mmo_char_sync(void)
         // yes, we need a mutable reference to do the saves ...
         for (mmo_charstatus& cd : char_data)
         {
-            FString line = mmo_char_tostr(&cd);
+            AString line = mmo_char_tostr(&cd);
             fp.put_line(line);
         }
         FPRINTF(fp, "%d\t%%newid%%\n", char_id_count);
@@ -1282,7 +1282,7 @@ void parse_tologin(Session *ls)
                     else
                     {
                         size_t len = RFIFOL(ls, 4);
-                        FString message = RFIFO_STRING(ls, 8, len).to_print().lstrip();
+                        AString message = RFIFO_STRING(ls, 8, len).to_print().lstrip();
                         // if message is only composed of spaces
                         if (!message)
                             CHAR_LOG("Receiving a message for broadcast, but message is only a lot of spaces.\n");
diff --git a/src/char/int_party.cpp b/src/char/int_party.cpp
index 79f24cb..cf9b3e5 100644
--- a/src/char/int_party.cpp
+++ b/src/char/int_party.cpp
@@ -4,7 +4,7 @@
 #include <cstring>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/xstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -21,7 +21,7 @@
 
 #include "../poison.hpp"
 
-FString party_txt = "save/party.txt";
+AString party_txt = "save/party.txt";
 
 static
 Map<int, struct party> party_db;
@@ -37,7 +37,7 @@ void mapif_parse_PartyLeave(Session *s, int party_id, int account_id);
 
 // パーティデータの文字列への変換
 static
-FString inter_party_tostr(struct party *p)
+AString inter_party_tostr(struct party *p)
 {
     MString str;
     str += STRPRINTF(
@@ -59,7 +59,7 @@ FString inter_party_tostr(struct party *p)
                 m->name);
     }
 
-    return FString(str);
+    return AString(str);
 }
 
 static
@@ -130,7 +130,7 @@ void inter_party_init(void)
         return;
 
     // TODO: convert to use char_id, and change to extract()
-    FString line;
+    AString line;
     int c = 0;
     while (in.getline(line))
     {
@@ -164,7 +164,7 @@ void inter_party_init(void)
 static
 void inter_party_save_sub(struct party *data, io::WriteFile& fp)
 {
-    FString line = inter_party_tostr(data);
+    AString line = inter_party_tostr(data);
     fp.put_line(line);
 }
 
@@ -701,7 +701,7 @@ int inter_party_parse_frommap(Session *ms)
             size_t len = RFIFOW(ms, 2) - 12;
             int party_id = RFIFOL(ms, 4);
             int account_id = RFIFOL(ms, 8);
-            FString mes = RFIFO_STRING(ms, 12, len);
+            AString mes = RFIFO_STRING(ms, 12, len);
             mapif_parse_PartyMessage(ms,
                     party_id,
                     account_id,
diff --git a/src/char/int_party.hpp b/src/char/int_party.hpp
index a5b6e8b..e4dedd1 100644
--- a/src/char/int_party.hpp
+++ b/src/char/int_party.hpp
@@ -12,6 +12,6 @@ int inter_party_parse_frommap(Session *ms);
 
 void inter_party_leave(int party_id, int account_id);
 
-extern FString party_txt;
+extern AString party_txt;
 
 #endif // INT_PARTY_HPP
diff --git a/src/char/int_storage.cpp b/src/char/int_storage.cpp
index c21da81..cdc6e05 100644
--- a/src/char/int_storage.cpp
+++ b/src/char/int_storage.cpp
@@ -6,7 +6,7 @@
 #include <functional>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/xstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -22,14 +22,14 @@
 
 // ファイル名のデフォルト
 // inter_config_read()で再設定される
-FString storage_txt = "save/storage.txt";
+AString storage_txt = "save/storage.txt";
 
 static
 Map<int, struct storage> storage_db;
 
 // 倉庫データを文字列に変換
 static
-FString storage_tostr(struct storage *p)
+AString storage_tostr(struct storage *p)
 {
     MString str;
     str += STRPRINTF(
@@ -59,8 +59,8 @@ FString storage_tostr(struct storage *p)
     str += '\t';
 
     if (!f)
-        return FString();
-    return FString(str);
+        return AString();
+    return AString(str);
 }
 
 // 文字列を倉庫データに変換
@@ -111,7 +111,7 @@ void inter_storage_init(void)
         return;
     }
 
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         struct storage s {};
@@ -131,7 +131,7 @@ void inter_storage_init(void)
 static
 void inter_storage_save_sub(struct storage *data, io::WriteFile& fp)
 {
-    FString line = storage_tostr(data);
+    AString line = storage_tostr(data);
     if (line)
         fp.put_line(line);
 }
diff --git a/src/char/int_storage.hpp b/src/char/int_storage.hpp
index 0790b6e..7081f30 100644
--- a/src/char/int_storage.hpp
+++ b/src/char/int_storage.hpp
@@ -12,6 +12,6 @@ struct storage *account2storage(int account_id);
 
 int inter_storage_parse_frommap(Session *ms);
 
-extern FString storage_txt;
+extern AString storage_txt;
 
 #endif // INT_STORAGE_HPP
diff --git a/src/char/inter.cpp b/src/char/inter.cpp
index 19ba254..192ffd5 100644
--- a/src/char/inter.cpp
+++ b/src/char/inter.cpp
@@ -7,7 +7,7 @@
 #include <vector>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -29,7 +29,7 @@
 #include "../poison.hpp"
 
 static
-FString accreg_txt = "save/accreg.txt";
+AString accreg_txt = "save/accreg.txt";
 
 struct accreg
 {
@@ -60,13 +60,13 @@ int inter_recv_packet_length[] =
 
 // アカウント変数を文字列へ変換
 static
-FString inter_accreg_tostr(struct accreg *reg)
+AString inter_accreg_tostr(struct accreg *reg)
 {
     MString str;
     str += STRPRINTF("%d\t", reg->account_id);
     for (int j = 0; j < reg->reg_num; j++)
         str += STRPRINTF("%s,%d ", reg->reg[j].str, reg->reg[j].value);
-    return FString(str);
+    return AString(str);
 }
 
 // アカウント変数を文字列から変換
@@ -98,7 +98,7 @@ void inter_accreg_init(void)
     io::ReadFile in(accreg_txt);
     if (!in.is_open())
         return;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         struct accreg reg {};
@@ -121,7 +121,7 @@ void inter_accreg_save_sub(struct accreg *reg, io::WriteFile& fp)
 {
     if (reg->reg_num > 0)
     {
-        FString line = inter_accreg_tostr(reg);
+        AString line = inter_accreg_tostr(reg);
         fp.put_line(line);
     }
 }
@@ -282,7 +282,7 @@ void mapif_parse_GMmessage(Session *s)
 {
     size_t msg_len = RFIFOW(s, 2);
     size_t str_len = msg_len - 4;
-    FString buf = RFIFO_STRING(s, 4, str_len);
+    AString buf = RFIFO_STRING(s, 4, str_len);
 
     mapif_GMmessage(buf);
 }
@@ -328,7 +328,7 @@ void mapif_parse_WisRequest(Session *sms)
         {
             size_t len = RFIFOW(sms, 2) - 52;
             Session *tms = server_for(mcs); // for to
-            FString msg = RFIFO_STRING(sms, 52, len);
+            AString msg = RFIFO_STRING(sms, 52, len);
             if (tms)
             {
                 mapif_wis_message(tms, from, to, msg);
diff --git a/src/common/dumb_ptr.hpp b/src/common/dumb_ptr.hpp
index 1ac237a..bf97f22 100644
--- a/src/common/dumb_ptr.hpp
+++ b/src/common/dumb_ptr.hpp
@@ -25,7 +25,7 @@
 
 # include <algorithm>
 
-# include "../strings/fstring.hpp"
+# include "../strings/astring.hpp"
 # include "../strings/zstring.hpp"
 # include "../strings/xstring.hpp"
 
@@ -246,7 +246,7 @@ struct dumb_string
         return ZString(strings::really_construct_from_a_pointer, c_str(), nullptr);
     }
 
-    FString str() const
+    AString str() const
     {
         return ZString(*this);
     }
diff --git a/src/common/extract.cpp b/src/common/extract.cpp
index bac7b38..5c07e24 100644
--- a/src/common/extract.cpp
+++ b/src/common/extract.cpp
@@ -18,7 +18,7 @@
 //    You should have received a copy of the GNU General Public License
 //    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/xstring.hpp"
 #include "../strings/vstring.hpp"
 
@@ -30,7 +30,7 @@ bool extract(XString str, XString *rv)
     return true;
 }
 
-bool extract(XString str, FString *rv)
+bool extract(XString str, AString *rv)
 {
     *rv = str;
     return true;
diff --git a/src/common/extract.hpp b/src/common/extract.hpp
index e798204..31cf111 100644
--- a/src/common/extract.hpp
+++ b/src/common/extract.hpp
@@ -84,7 +84,7 @@ bool extract(XString str, T *iv)
 
 bool extract(XString str, XString *rv);
 
-bool extract(XString str, FString *rv);
+bool extract(XString str, AString *rv);
 
 template<uint8_t N>
 bool extract(XString str, VString<N> *out)
diff --git a/src/common/intern-pool.hpp b/src/common/intern-pool.hpp
index 163e5cc..e75a359 100644
--- a/src/common/intern-pool.hpp
+++ b/src/common/intern-pool.hpp
@@ -6,18 +6,19 @@
 # include <map>
 # include <vector>
 
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
 # include "../strings/zstring.hpp"
 # include "../strings/xstring.hpp"
 
 class InternPool
 {
-    std::map<FString, size_t> known;
-    std::vector<FString> names;
+    std::map<RString, size_t> known;
+    std::vector<RString> names;
 public:
     size_t intern(XString name_)
     {
-        FString name = name_;
+        // TODO just look up the XString, the memory should not move by now
+        RString name = name_;
         // hm, I could change this to do aliases
         auto pair = known.insert({name, known.size()});
         if (pair.second)
diff --git a/src/common/mmo.hpp b/src/common/mmo.hpp
index 8b18181..b2f36b6 100644
--- a/src/common/mmo.hpp
+++ b/src/common/mmo.hpp
@@ -69,7 +69,8 @@ public:
     iterator end() const { return &*_impl.end(); }
     const char *c_str() const { return _impl.c_str(); }
 
-    operator FString() const { return _impl; }
+    operator RString() const { return _impl; }
+    operator AString() const { return _impl; }
     operator TString() const { return _impl; }
     operator SString() const { return _impl; }
     operator ZString() const { return _impl; }
diff --git a/src/common/socket.hpp b/src/common/socket.hpp
index 6d0ca01..e0847ac 100644
--- a/src/common/socket.hpp
+++ b/src/common/socket.hpp
@@ -9,7 +9,7 @@
 
 # include <array>
 
-# include "../strings/fstring.hpp"
+# include "../strings/astring.hpp"
 # include "../strings/vstring.hpp"
 # include "../strings/xstring.hpp"
 
@@ -183,7 +183,7 @@ VString<len-1> RFIFO_STRING(Session *s, size_t pos)
     return XString(begin, mid, nullptr);
 }
 inline
-FString RFIFO_STRING(Session *s, size_t pos, size_t len)
+AString RFIFO_STRING(Session *s, size_t pos, size_t len)
 {
     const char *const begin = static_cast<const char *>(RFIFOP(s, pos));
     const char *const end = begin + len;
@@ -242,7 +242,7 @@ VString<len-1> RBUF_STRING(const uint8_t *p, size_t pos)
     return XString(begin, mid, nullptr);
 }
 inline
-FString RBUF_STRING(const uint8_t *p, size_t pos, size_t len)
+AString RBUF_STRING(const uint8_t *p, size_t pos, size_t len)
 {
     const char *const begin = static_cast<const char *>(RBUFP(p, pos));
     const char *const end = begin + len;
diff --git a/src/common/utils.cpp b/src/common/utils.cpp
index 3a26e6d..0dbf145 100644
--- a/src/common/utils.cpp
+++ b/src/common/utils.cpp
@@ -5,7 +5,7 @@
 
 #include <algorithm>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
diff --git a/src/io/cxxstdio.hpp b/src/io/cxxstdio.hpp
index b4b4c79..753a1fc 100644
--- a/src/io/cxxstdio.hpp
+++ b/src/io/cxxstdio.hpp
@@ -238,15 +238,15 @@ namespace cxxstdio
 # define FPRINTF(file, fmt, ...)     XPRINTF(/*no_cast<FILE *>*/(file), fmt, ## __VA_ARGS__)
 # define FSCANF(file, fmt, ...)      XSCANF(no_cast<FILE *>(file), fmt, ## __VA_ARGS__)
 # define PRINTF(fmt, ...)            FPRINTF(stdout, fmt, ## __VA_ARGS__)
-# define SPRINTF(str, fmt, ...)      XPRINTF(base_cast<FString&>(str), fmt, ## __VA_ARGS__)
+# define SPRINTF(str, fmt, ...)      XPRINTF(base_cast<AString&>(str), fmt, ## __VA_ARGS__)
 # define SNPRINTF(str, n, fmt, ...)  XPRINTF(base_cast<VString<n-1>&>(str), fmt, ## __VA_ARGS__)
 # define SCANF(fmt, ...)             FSCANF(stdin, fmt, ## __VA_ARGS__)
 # define SSCANF(str, fmt, ...)       XSCANF(/*ZString or compatible*/str, fmt, ## __VA_ARGS__)
 
 # define STRPRINTF(fmt, ...)                        \
-    (/*[&]() -> FString*/                           \
+    (/*[&]() -> AString*/                           \
     {                                               \
-        FString _out_impl;                          \
+        AString _out_impl;                          \
         SPRINTF(_out_impl, fmt, ## __VA_ARGS__);    \
         /*return*/ _out_impl;                       \
     }/*()*/)
diff --git a/src/io/line.cpp b/src/io/line.cpp
index 83f439d..fb73f45 100644
--- a/src/io/line.cpp
+++ b/src/io/line.cpp
@@ -21,7 +21,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/mstring.hpp"
 #include "../strings/zstring.hpp"
 
@@ -32,7 +32,7 @@
 
 namespace io
 {
-    FString Line::message_str(ZString cat, ZString msg)
+    AString Line::message_str(ZString cat, ZString msg)
     {
         MString out;
         if (column)
@@ -43,7 +43,7 @@ namespace io
                     filename, line, cat, msg);
         out += STRPRINTF("%s\n", text);
         out += STRPRINTF("%*c\n", column, '^');
-        return FString(out);
+        return AString(out);
     }
 
     void Line::message(ZString cat, ZString msg)
@@ -68,8 +68,10 @@ namespace io
 
     bool LineReader::read_line(Line& l)
     {
-        if (rf.getline(l.text))
+        AString text;
+        if (rf.getline(text))
         {
+            l.text = text;
             l.filename = filename;
             l.line = ++line;
             l.column = 0; // whole line
diff --git a/src/io/line.hpp b/src/io/line.hpp
index 00f0a11..bdff1bb 100644
--- a/src/io/line.hpp
+++ b/src/io/line.hpp
@@ -21,7 +21,8 @@
 
 # include "../sanity.hpp"
 
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
+# include "../strings/astring.hpp"
 # include "../strings/zstring.hpp"
 
 # include "fd.hpp"
@@ -30,15 +31,16 @@
 
 namespace io
 {
+    // TODO split this out
     struct Line
     {
-        FString text;
+        RString text;
 
-        FString filename;
+        RString filename;
         // 1-based
         uint16_t line, column;
 
-        FString message_str(ZString cat, ZString msg);
+        AString message_str(ZString cat, ZString msg);
         void message(ZString cat, ZString msg);
         void note(ZString msg) { message("note", msg); }
         void warning(ZString msg) { message("warning", msg); }
@@ -60,7 +62,7 @@ namespace io
     class LineReader
     {
     protected:
-        FString filename;
+        RString filename;
         uint16_t line, column;
         ReadFile rf;
     public:
@@ -77,7 +79,7 @@ namespace io
 
     class LineCharReader : private LineReader
     {
-        FString line_text;
+        RString line_text;
     public:
         explicit
         LineCharReader(ZString name);
diff --git a/src/io/lock.cpp b/src/io/lock.cpp
index c7cbda8..96c3649 100644
--- a/src/io/lock.cpp
+++ b/src/io/lock.cpp
@@ -46,7 +46,7 @@ namespace io
         int no = getpid();
 
         // Get a filename that doesn't already exist
-        FString newfile;
+        AString newfile;
         do
         {
             newfile = STRPRINTF("%s_%d.tmp", filename, no++);
@@ -59,7 +59,7 @@ namespace io
         return fd;
     }
 
-    WriteLock::WriteLock(FString fn, bool linebuffered)
+    WriteLock::WriteLock(RString fn, bool linebuffered)
     : WriteFile(get_lock_open(fn, &tmp_suffix), linebuffered), filename(fn)
     {}
     WriteLock::~WriteLock()
@@ -72,16 +72,16 @@ namespace io
         }
 
         int n = backup_count;
-        FString old_filename = STRPRINTF("%s.%d", filename, n);
+        AString old_filename = STRPRINTF("%s.%d", filename, n);
         while (--n)
         {
-            FString newer_filename = STRPRINTF("%s.%d", filename, n);
+            AString newer_filename = STRPRINTF("%s.%d", filename, n);
             rename(newer_filename.c_str(), old_filename.c_str());
             old_filename = std::move(newer_filename);
         }
         rename(filename.c_str(), old_filename.c_str());
 
-        FString tmpfile = STRPRINTF("%s_%d.tmp", filename, tmp_suffix);
+        AString tmpfile = STRPRINTF("%s_%d.tmp", filename, tmp_suffix);
         rename(tmpfile.c_str(), filename.c_str());
     }
 } // namespace io
diff --git a/src/io/lock.hpp b/src/io/lock.hpp
index a19acdb..b5052cf 100644
--- a/src/io/lock.hpp
+++ b/src/io/lock.hpp
@@ -21,17 +21,17 @@
 
 # include "write.hpp"
 
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
 
 
 namespace io
 {
     class WriteLock : public WriteFile
     {
-        FString filename;
+        RString filename;
         int tmp_suffix;
     public:
-        WriteLock(FString filename, bool linebuffered=false);
+        WriteLock(RString filename, bool linebuffered=false);
         ~WriteLock();
         bool close() = delete;
     };
diff --git a/src/io/read.cpp b/src/io/read.cpp
index fe2c765..2ef35cc 100644
--- a/src/io/read.cpp
+++ b/src/io/read.cpp
@@ -21,7 +21,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/mstring.hpp"
 #include "../strings/zstring.hpp"
 
@@ -74,7 +74,7 @@ namespace io
         }
         return len;
     }
-    bool ReadFile::getline(FString& line)
+    bool ReadFile::getline(AString& line)
     {
         MString tmp;
         char c;
@@ -111,7 +111,7 @@ namespace io
         }
         else if (!happy && anything)
             PRINTF("warning: file does not contain a trailing newline\n");
-        line = FString(tmp);
+        line = AString(tmp);
         return anything;
     }
 
diff --git a/src/io/read.hpp b/src/io/read.hpp
index 4830fa4..2355e46 100644
--- a/src/io/read.hpp
+++ b/src/io/read.hpp
@@ -44,7 +44,7 @@ namespace io
 
         bool get(char&);
         size_t get(char *buf, size_t len);
-        bool getline(FString&);
+        bool getline(AString&);
 
         bool is_open();
     };
diff --git a/src/io/read_test.cpp b/src/io/read_test.cpp
index ebb20ca..5d287dd 100644
--- a/src/io/read_test.cpp
+++ b/src/io/read_test.cpp
@@ -23,7 +23,7 @@ io::FD string_pipe(ZString sz)
 TEST(io, read1)
 {
     io::ReadFile rf(string_pipe("Hello"));
-    FString hi;
+    AString hi;
     EXPECT_TRUE(rf.getline(hi));
     EXPECT_EQ(hi, "Hello");
     EXPECT_FALSE(rf.getline(hi));
@@ -31,7 +31,7 @@ TEST(io, read1)
 TEST(io, read2)
 {
     io::ReadFile rf(string_pipe("Hello\n"));
-    FString hi;
+    AString hi;
     EXPECT_TRUE(rf.getline(hi));
     EXPECT_EQ(hi, "Hello");
     EXPECT_FALSE(rf.getline(hi));
@@ -39,7 +39,7 @@ TEST(io, read2)
 TEST(io, read3)
 {
     io::ReadFile rf(string_pipe("Hello\r"));
-    FString hi;
+    AString hi;
     EXPECT_TRUE(rf.getline(hi));
     EXPECT_EQ(hi, "Hello");
     EXPECT_FALSE(rf.getline(hi));
@@ -47,7 +47,7 @@ TEST(io, read3)
 TEST(io, read4)
 {
     io::ReadFile rf(string_pipe("Hello\r\n"));
-    FString hi;
+    AString hi;
     EXPECT_TRUE(rf.getline(hi));
     EXPECT_EQ(hi, "Hello");
     EXPECT_FALSE(rf.getline(hi));
@@ -55,7 +55,7 @@ TEST(io, read4)
 TEST(io, read5)
 {
     io::ReadFile rf(string_pipe("Hello\n\r"));
-    FString hi;
+    AString hi;
     EXPECT_TRUE(rf.getline(hi));
     EXPECT_EQ(hi, "Hello");
     EXPECT_TRUE(rf.getline(hi));
diff --git a/src/io/write_test.cpp b/src/io/write_test.cpp
index a9736b8..f703850 100644
--- a/src/io/write_test.cpp
+++ b/src/io/write_test.cpp
@@ -5,7 +5,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/mstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -35,7 +35,7 @@ public:
     {
         rfd.close();
     }
-    FString slurp()
+    AString slurp()
     {
         MString tmp;
         char buf[4096];
@@ -52,7 +52,7 @@ public:
                 break;
             tmp += XString(buf + 0, buf + rv, nullptr);
         }
-        return FString(tmp);
+        return AString(tmp);
     }
 };
 
@@ -73,10 +73,10 @@ TEST(io, write2)
     PipeWriter pw(true);
     io::WriteFile& wf = pw.wf;
     wf.really_put("Hello, ", 7);
-    EXPECT_EQ("", std::string(pw.slurp().c_str()));
+    EXPECT_EQ("", pw.slurp());
     wf.put_line("World!");
     wf.really_put("XXX", 3);
-    EXPECT_EQ("Hello, World!\n", std::string(pw.slurp().c_str()));
+    EXPECT_EQ("Hello, World!\n", pw.slurp());
     EXPECT_TRUE(wf.close());
-    EXPECT_EQ("XXX", std::string(pw.slurp().c_str()));
+    EXPECT_EQ("XXX", pw.slurp());
 }
diff --git a/src/login/login.cpp b/src/login/login.cpp
index b1d37dc..ea58669 100644
--- a/src/login/login.cpp
+++ b/src/login/login.cpp
@@ -15,7 +15,7 @@
 #include <type_traits>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 #include "../strings/vstring.hpp"
@@ -80,7 +80,7 @@ IP4Address lan_char_ip = IP4_LOCALHOST;
 static
 IP4Mask lan_subnet = IP4Mask(IP4_LOCALHOST, IP4_BROADCAST);
 static
-FString update_host;
+AString update_host;
 static
 AccountName userid;
 static
@@ -89,13 +89,13 @@ static
 ServerName main_server;
 
 static
-FString account_filename = "save/account.txt";
+AString account_filename = "save/account.txt";
 static
-FString gm_account_filename = "save/gm_account.txt";
+AString gm_account_filename = "save/gm_account.txt";
 static
-FString login_log_filename = "log/login.log";
+AString login_log_filename = "log/login.log";
 static
-FString login_log_unknown_packets_filename = "log/login_unknown_packets.log";
+AString login_log_unknown_packets_filename = "log/login_unknown_packets.log";
 static
 int save_unknown_packets = 0;
 static
@@ -191,7 +191,7 @@ int admin_state = 0;
 static
 AccountPass admin_pass;
 static
-FString gm_pass;
+AString gm_pass;
 static
 int level_new_gm = 60;
 
@@ -268,7 +268,7 @@ int read_gm_account(void)
     }
     // limited to 4000, because we send information to char-servers (more than 4000 GM accounts???)
     // int (id) + int (level) = 8 bytes * 4000 = 32k (limit of packets in windows)
-    FString line;
+    AString line;
     while (fp.getline(line) && c < 4000)
     {
         if (is_comment(line))
@@ -413,7 +413,7 @@ AuthData *search_account(AccountName account_name)
 // Create a string to save the account in the account file
 //--------------------------------------------------------
 static
-FString mmo_auth_tostr(const AuthData *p)
+AString mmo_auth_tostr(const AuthData *p)
 {
     MString str;
     str += STRPRINTF(
@@ -449,7 +449,7 @@ FString mmo_auth_tostr(const AuthData *p)
             str += STRPRINTF("%s,%d ",
                     p->account_reg2[i].str, p->account_reg2[i].value);
 
-    return FString(str);
+    return AString(str);
 }
 
 static
@@ -543,7 +543,7 @@ int mmo_auth_init(void)
         return 0;
     }
 
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         if (is_comment(line))
@@ -574,7 +574,7 @@ int mmo_auth_init(void)
             account_id_count = ad.account_id + 1;
     }
 
-    FString str = STRPRINTF("%s has %zu accounts (%d GMs)\n",
+    AString str = STRPRINTF("%s has %zu accounts (%d GMs)\n",
             account_filename, auth_data.size(), gm_count);
     PRINTF("%s: %s\n", __PRETTY_FUNCTION__, str);
     LOGIN_LOG("%s\n", line);
@@ -621,7 +621,7 @@ void mmo_auth_sync(void)
         if (ad.account_id < 0)
             continue;
 
-        FString line = mmo_auth_tostr(&ad);
+        AString line = mmo_auth_tostr(&ad);
         fp.put_line(line);
     }
     FPRINTF(fp, "%d\t%%newid%%\n", account_id_count);
@@ -1112,7 +1112,7 @@ void parse_fromchar(Session *s)
                     WBUFL(buf, 2) = acc;
                     WBUFL(buf, 6) = 0;
                     size_t len = RFIFOW(s, 2) - 8;
-                    FString pass = RFIFO_STRING(s, 8, len);
+                    AString pass = RFIFO_STRING(s, 8, len);
 
                     if (pass == gm_pass)
                     {
@@ -1740,7 +1740,7 @@ void parse_admin(Session *s)
                          ad->userid, ad->account_id,
                          ip);
                     {
-                        FString buf2 = mmo_auth_tostr(ad);
+                        AString buf2 = mmo_auth_tostr(ad);
                         LOGIN_LOG("%s\n", buf2);
                     }
                     // delete account
@@ -2000,7 +2000,7 @@ void parse_admin(Session *s)
                                         stamp_time(tmpstr);
                                         modify_flag = 0;
                                         // read/write GM file
-                                        FString line;
+                                        AString line;
                                         while (fp.getline(line))
                                         {
                                             if (is_comment(line))
@@ -2426,7 +2426,7 @@ void parse_admin(Session *s)
                         WFIFOW(s, 2) = 0;
 
                         size_t len = RFIFOL(s, 4);
-                        FString message = RFIFO_STRING(s, 8, len).to_print();
+                        AString message = RFIFO_STRING(s, 8, len).to_print();
                         LOGIN_LOG("'ladmin': Receiving a message for broadcast (message: %s, ip: %s)\n",
                                 message, ip);
                         // send same message to all char-servers (no answer)
diff --git a/src/map/atcommand.cpp b/src/map/atcommand.cpp
index f5deab8..dca9b4e 100644
--- a/src/map/atcommand.cpp
+++ b/src/map/atcommand.cpp
@@ -5,7 +5,7 @@
 #include <ctime>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 #include "../strings/vstring.hpp"
@@ -182,7 +182,7 @@ void log_atcommand(dumb_ptr<map_session_data> sd, ZString cmd)
             cmd);
 }
 
-FString gm_log;
+AString gm_log;
 
 io::AppendFile *get_gm_log()
 {
@@ -201,7 +201,7 @@ io::AppendFile *get_gm_log()
         return gm_logfile.get();
     last_logfile_nr = logfile_nr;
 
-    FString fullname = STRPRINTF("%s.%04d-%02d",
+    AString fullname = STRPRINTF("%s.%04d-%02d",
             gm_log, year, month);
 
     if (gm_logfile)
@@ -212,7 +212,7 @@ io::AppendFile *get_gm_log()
     if (!gm_logfile)
     {
         perror("GM log file");
-        gm_log = FString();
+        gm_log = AString();
     }
     return gm_logfile.get();
 }
@@ -235,24 +235,24 @@ bool is_atcommand(Session *s, dumb_ptr<map_session_data> sd,
         gmlvl = pc_isGM(sd);
     if (battle_config.atcommand_gm_only != 0 && !gmlvl)
     {
-        FString output = STRPRINTF("GM command is level 0, but this server disables level 0 commands: %s",
-                FString(command));
+        AString output = STRPRINTF("GM command is level 0, but this server disables level 0 commands: %s",
+                AString(command));
         clif_displaymessage(s, output);
         return true;
     }
     if (!info)
     {
-        FString output = STRPRINTF("GM command not found: %s",
-                FString(command));
+        AString output = STRPRINTF("GM command not found: %s",
+                AString(command));
         clif_displaymessage(s, output);
         return true;
         // don't show in chat
     }
     if (info->level > gmlvl)
     {
-        FString output = STRPRINTF("GM command is level %d, but you are level %d: %s",
+        AString output = STRPRINTF("GM command is level %d, but you are level %d: %s",
                 info->level, gmlvl,
-                FString(command));
+                AString(command));
         clif_displaymessage(s, output);
         return true;
     }
@@ -269,7 +269,7 @@ bool is_atcommand(Session *s, dumb_ptr<map_session_data> sd,
                 break;
             case ATCE::USAGE:
                 clif_displaymessage(s, "Command failed: usage error");
-                clif_displaymessage(s, STRPRINTF("Usage: %s %s", FString(command), info->args));
+                clif_displaymessage(s, STRPRINTF("Usage: %s %s", AString(command), info->args));
                 break;
             case ATCE::EXIST:
                 clif_displaymessage(s, "Command failed: something does not exist (or already exists)");
@@ -328,7 +328,7 @@ bool atcommand_config_read(ZString cfgName)
     }
 
     bool rv = true;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         if (is_comment(line))
@@ -442,7 +442,7 @@ ATCE atcommand_setup(Session *s, dumb_ptr<map_session_data> sd,
         return ATCE::USAGE;
     level--;
 
-    FString buf;
+    AString buf;
     buf = STRPRINTF("-255 %s", character);
     atcommand_character_baselevel(s, sd, buf);
 
@@ -606,7 +606,7 @@ ATCE atcommand_where(Session *s, dumb_ptr<map_session_data> sd,
           && (pc_isGM(pl_sd) > pc_isGM(sd))))
     {
         // you can look only lower or same level
-        FString output = STRPRINTF("%s: %s (%d,%d)",
+        AString output = STRPRINTF("%s: %s (%d,%d)",
                 pl_sd->status.name,
                 pl_sd->mapname_, pl_sd->bl_x, pl_sd->bl_y);
         clif_displaymessage(s, output);
@@ -651,7 +651,7 @@ ATCE atcommand_goto(Session *s, dumb_ptr<map_session_data> sd,
             return ATCE::PERM;
         }
         pc_setpos(sd, pl_sd->mapname_, pl_sd->bl_x, pl_sd->bl_y, BeingRemoveWhy::WARPED);
-        FString output = STRPRINTF("Jump to %s", character);
+        AString output = STRPRINTF("Jump to %s", character);
         clif_displaymessage(s, output);
     }
     else
@@ -692,7 +692,7 @@ ATCE atcommand_jump(Session *s, dumb_ptr<map_session_data> sd,
             return ATCE::PERM;
         }
         pc_setpos(sd, sd->mapname_, x, y, BeingRemoveWhy::WARPED);
-        FString output = STRPRINTF("Jump to %d %d", x, y);
+        AString output = STRPRINTF("Jump to %d %d", x, y);
         clif_displaymessage(s, output);
     }
     else
@@ -734,7 +734,7 @@ ATCE atcommand_who(Session *s, dumb_ptr<map_session_data> sd,
                 if (player_name.contains_seq(match_text))
                 {
                     // search with no case sensitive
-                    FString output;
+                    AString output;
                     if (pl_GM_level > 0)
                         output = STRPRINTF(
                                 "Name: %s (GM:%d) | Location: %s %d %d",
@@ -758,7 +758,7 @@ ATCE atcommand_who(Session *s, dumb_ptr<map_session_data> sd,
         clif_displaymessage(s, "1 player found.");
     else
     {
-        FString output = STRPRINTF("%d players found.", count);
+        AString output = STRPRINTF("%d players found.", count);
         clif_displaymessage(s, output);
     }
 
@@ -799,7 +799,7 @@ ATCE atcommand_whogroup(Session *s, dumb_ptr<map_session_data> sd,
                     // search with no case sensitive
                     p = party_search(pl_sd->status.party_id);
                     PartyName temp0 = p ? p->name : stringish<PartyName>("None");
-                    FString output;
+                    AString output;
                     if (pl_GM_level > 0)
                         output = STRPRINTF(
                                 "Name: %s (GM:%d) | Party: '%s'",
@@ -817,7 +817,7 @@ ATCE atcommand_whogroup(Session *s, dumb_ptr<map_session_data> sd,
         clif_displaymessage(s, "1 player found.");
     else
     {
-        FString output = STRPRINTF("%d players found.", count);
+        AString output = STRPRINTF("%d players found.", count);
         clif_displaymessage(s, output);
     }
 
@@ -859,7 +859,7 @@ ATCE atcommand_whomap(Session *s, dumb_ptr<map_session_data> sd,
                 // you can look only lower or same level
                 if (pl_sd->bl_m == map_id)
                 {
-                    FString output;
+                    AString output;
                     if (pl_GM_level > 0)
                         output = STRPRINTF(
                                 "Name: %s (GM:%d) | Location: %s %d %d",
@@ -877,7 +877,7 @@ ATCE atcommand_whomap(Session *s, dumb_ptr<map_session_data> sd,
         }
     }
 
-    FString output = STRPRINTF("%d players found in map '%s'.",
+    AString output = STRPRINTF("%d players found in map '%s'.",
             count, map_id->name_);
     clif_displaymessage(s, output);
 
@@ -922,7 +922,7 @@ ATCE atcommand_whomapgroup(Session *s, dumb_ptr<map_session_data> sd,
                 {
                     p = party_search(pl_sd->status.party_id);
                     PartyName temp0 = p ? p->name : stringish<PartyName>("None");
-                    FString output;
+                    AString output;
                     if (pl_GM_level > 0)
                         output = STRPRINTF("Name: %s (GM:%d) | Party: '%s'",
                                 pl_sd->status.name, pl_GM_level, temp0);
@@ -936,7 +936,7 @@ ATCE atcommand_whomapgroup(Session *s, dumb_ptr<map_session_data> sd,
         }
     }
 
-    FString output;
+    AString output;
     if (count == 0)
         output = STRPRINTF("No player found in map '%s'.", map_id->name_);
     else if (count == 1)
@@ -984,7 +984,7 @@ ATCE atcommand_whogm(Session *s, dumb_ptr<map_session_data> sd,
                     if (player_name.contains_seq(match_text))
                     {
                         // search with no case sensitive
-                        FString output;
+                        AString output;
                         output = STRPRINTF(
                                 "Name: %s (GM:%d) | Location: %s %d %d",
                                 pl_sd->status.name, pl_GM_level,
@@ -1015,7 +1015,7 @@ ATCE atcommand_whogm(Session *s, dumb_ptr<map_session_data> sd,
         clif_displaymessage(s, "1 GM found.");
     else
     {
-        FString output = STRPRINTF("%d GMs found.", count);
+        AString output = STRPRINTF("%d GMs found.", count);
         clif_displaymessage(s, output);
     }
 
@@ -1067,7 +1067,7 @@ ATCE atcommand_speed(Session *s, dumb_ptr<map_session_data> sd,
 {
     if (!message)
     {
-        FString output = STRPRINTF(
+        AString output = STRPRINTF(
                 "Please, enter a speed value (usage: @speed <%d-%d>).",
                 static_cast<uint32_t>(MIN_WALK_SPEED.count()),
                 static_cast<uint32_t>(MAX_WALK_SPEED.count()));
@@ -1086,7 +1086,7 @@ ATCE atcommand_speed(Session *s, dumb_ptr<map_session_data> sd,
     }
     else
     {
-        FString output = STRPRINTF(
+        AString output = STRPRINTF(
                 "Please, enter a valid speed value (usage: @speed <%d-%d>).",
                 static_cast<uint32_t>(MIN_WALK_SPEED.count()),
                 static_cast<uint32_t>(MAX_WALK_SPEED.count()));
@@ -1746,7 +1746,7 @@ ATCE atcommand_spawn(Session *s, dumb_ptr<map_session_data> sd,
             clif_displaymessage(s, "All monster summoned!");
         else
         {
-            FString output = STRPRINTF("%d monster(s) summoned!",
+            AString output = STRPRINTF("%d monster(s) summoned!",
                     count);
             clif_displaymessage(s, output);
         }
@@ -1795,7 +1795,7 @@ void atlist_nearby_sub(dumb_ptr<block_list> bl, Session *s)
 {
     nullpo_retv(bl);
 
-    FString buf = STRPRINTF(" - \"%s\"",
+    AString buf = STRPRINTF(" - \"%s\"",
             bl->is_player()->status.name);
     clif_displaymessage(s, buf);
 }
@@ -1831,7 +1831,7 @@ ATCE atcommand_gat(Session *s, dumb_ptr<map_session_data> sd,
 
     for (y = 2; y >= -2; y--)
     {
-        FString output = STRPRINTF(
+        AString output = STRPRINTF(
                 "%s (x= %d, y= %d) %02X %02X %02X %02X %02X",
                 sd->bl_m->name_, sd->bl_x - 2, sd->bl_y + y,
                 map_getcell(sd->bl_m, sd->bl_x - 2, sd->bl_y + y),
@@ -2049,7 +2049,7 @@ ATCE atcommand_recall(Session *s, dumb_ptr<map_session_data> sd,
                 return ATCE::PERM;
             }
             pc_setpos(pl_sd, sd->mapname_, sd->bl_x, sd->bl_y, BeingRemoveWhy::QUIT);
-            FString output = STRPRINTF("%s recalled!", character);
+            AString output = STRPRINTF("%s recalled!", character);
             clif_displaymessage(s, output);
         }
         else
@@ -2109,7 +2109,7 @@ ATCE atcommand_character_stats(Session *s, dumb_ptr<map_session_data>,
     dumb_ptr<map_session_data> pl_sd = map_nick2sd(character);
     if (pl_sd != NULL)
     {
-        FString output;
+        AString output;
         output = STRPRINTF("'%s' stats:", pl_sd->status.name);
         clif_displaymessage(s, output);
         output = STRPRINTF("Base Level - %d", pl_sd->status.base_level),
@@ -2163,13 +2163,13 @@ ATCE atcommand_character_stats_all(Session *s, dumb_ptr<map_session_data>,
         dumb_ptr<map_session_data> pl_sd = dumb_ptr<map_session_data>(static_cast<map_session_data *>(s2->session_data.get()));
         if (pl_sd && pl_sd->state.auth)
         {
-            FString gmlevel;
+            AString gmlevel;
             if (pc_isGM(pl_sd) > 0)
                 gmlevel = STRPRINTF("| GM Lvl: %d", pc_isGM(pl_sd));
             else
                 gmlevel = " ";
 
-            FString output;
+            AString output;
             output = STRPRINTF(
                     "Name: %s | BLvl: %d | Job: Novice/Human (Lvl: %d) | HP: %d/%d | SP: %d/%d",
                     pl_sd->status.name, pl_sd->status.base_level,
@@ -2198,7 +2198,7 @@ ATCE atcommand_character_stats_all(Session *s, dumb_ptr<map_session_data>,
         clif_displaymessage(s, "1 player found.");
     else
     {
-        FString output = STRPRINTF("%d players found.", count);
+        AString output = STRPRINTF("%d players found.", count);
         clif_displaymessage(s, output);
     }
 
@@ -2935,7 +2935,7 @@ ATCE atcommand_idsearch(Session *s, dumb_ptr<map_session_data>,
     if (!extract(message, &item_name) || !item_name)
         return ATCE::USAGE;
 
-    FString output = STRPRINTF("The reference result of '%s' (name: id):", item_name);
+    AString output = STRPRINTF("The reference result of '%s' (name: id):", item_name);
     clif_displaymessage(s, output);
     match = 0;
     for (i = 0; i < 20000; i++)
@@ -2970,7 +2970,7 @@ ATCE atcommand_charskreset(Session *s, dumb_ptr<map_session_data> sd,
         {
             // you can reset skill points only lower or same gm level
             pc_resetskill(pl_sd);
-            FString output = STRPRINTF(
+            AString output = STRPRINTF(
                     "'%s' skill points reseted!", character);
             clif_displaymessage(s, output);
         }
@@ -3005,7 +3005,7 @@ ATCE atcommand_charstreset(Session *s, dumb_ptr<map_session_data> sd,
         {
             // you can reset stats points only lower or same gm level
             pc_resetstate(pl_sd);
-            FString output = STRPRINTF(
+            AString output = STRPRINTF(
                     "'%s' stats points reseted!",
                     character);
             clif_displaymessage(s, output);
@@ -3046,7 +3046,7 @@ ATCE atcommand_charreset(Session *s, dumb_ptr<map_session_data> sd,
             // [Fate] Reset magic quest variables
             pc_setglobalreg(pl_sd, stringish<VarName>("MAGIC_EXP"), 0);
             // [Fate] Reset magic experience
-            FString output = STRPRINTF(
+            AString output = STRPRINTF(
                     "'%s' skill and stats points reseted!", character);
             clif_displaymessage(s, output);
         }
@@ -3131,7 +3131,7 @@ ATCE atcommand_char_wipe(Session *s, dumb_ptr<map_session_data> sd,
             pc_setglobalreg(pl_sd, stringish<VarName>("MAGIC_EXP"), 0);
             // [Fate] Reset magic experience
 
-            FString output = STRPRINTF("%s:  wiped.", character);
+            AString output = STRPRINTF("%s:  wiped.", character);
             clif_displaymessage(s, output);
         }
         else
@@ -3341,7 +3341,7 @@ ATCE atcommand_recallall(Session *s, dumb_ptr<map_session_data> sd,
     clif_displaymessage(s, "All characters recalled!");
     if (count)
     {
-        FString output = STRPRINTF(
+        AString output = STRPRINTF(
                 "Because you are not authorised to warp from some maps, %d player(s) have not been recalled.",
                 count);
         clif_displaymessage(s, output);
@@ -3391,7 +3391,7 @@ ATCE atcommand_partyrecall(Session *s, dumb_ptr<map_session_data> sd,
                     pc_setpos(pl_sd, sd->mapname_, sd->bl_x, sd->bl_y, BeingRemoveWhy::QUIT);
             }
         }
-        FString output = STRPRINTF("All online characters of the %s party are near you.", p->name);
+        AString output = STRPRINTF("All online characters of the %s party are near you.", p->name);
         clif_displaymessage(s, output);
         if (count)
         {
@@ -3432,7 +3432,7 @@ ATCE atcommand_mapinfo(Session *s, dumb_ptr<map_session_data> sd,
         return ATCE::EXIST;
 
     clif_displaymessage(s, "------ Map Info ------");
-    FString output = STRPRINTF("Map Name: %s", map_name);
+    AString output = STRPRINTF("Map Name: %s", map_name);
     clif_displaymessage(s, output);
     output = STRPRINTF("Players In Map: %d", m_id->users);
     clif_displaymessage(s, output);
@@ -3565,13 +3565,13 @@ ATCE atcommand_partyspy(Session *s, dumb_ptr<map_session_data> sd,
         if (sd->partyspy == p->party_id)
         {
             sd->partyspy = 0;
-            FString output = STRPRINTF("No longer spying on the %s party.", p->name);
+            AString output = STRPRINTF("No longer spying on the %s party.", p->name);
             clif_displaymessage(s, output);
         }
         else
         {
             sd->partyspy = p->party_id;
-            FString output = STRPRINTF("Spying on the %s party.", p->name);
+            AString output = STRPRINTF("Spying on the %s party.", p->name);
             clif_displaymessage(s, output);
         }
     }
@@ -3636,7 +3636,7 @@ ATCE atcommand_servertime(Session *s, dumb_ptr<map_session_data>,
 {
     timestamp_seconds_buffer tsbuf;
     stamp_time(tsbuf);
-    FString temp = STRPRINTF("Server time: %s", tsbuf);
+    AString temp = STRPRINTF("Server time: %s", tsbuf);
     clif_displaymessage(s, temp);
 
     return ATCE::OKAY;
@@ -3678,7 +3678,7 @@ ATCE atcommand_chardelitem(Session *s, dumb_ptr<map_session_data> sd,
                         item_position = pc_search_inventory(pl_sd, item_id);
                         // for next loop
                     }
-                    FString output = STRPRINTF(
+                    AString output = STRPRINTF(
                             "%d item(s) removed by a GM.",
                             count);
                     clif_displaymessage(pl_sd->sess, output);
@@ -3723,7 +3723,7 @@ ATCE atcommand_broadcast(Session *, dumb_ptr<map_session_data> sd,
     if (!message)
         return ATCE::USAGE;
 
-    FString output = STRPRINTF("%s : %s", sd->status.name, message);
+    AString output = STRPRINTF("%s : %s", sd->status.name, message);
     intif_GMmessage(output);
 
     return ATCE::OKAY;
@@ -3736,7 +3736,7 @@ ATCE atcommand_localbroadcast(Session *, dumb_ptr<map_session_data> sd,
     if (!message)
         return ATCE::USAGE;
 
-    FString output = STRPRINTF("%s : %s", sd->status.name, message);
+    AString output = STRPRINTF("%s : %s", sd->status.name, message);
 
     clif_GMmessage(sd, output, 1);
 
@@ -3844,7 +3844,7 @@ ATCE atcommand_character_item_list(Session *s, dumb_ptr<map_session_data> sd,
                     count++;
                     if (count == 1)
                     {
-                        FString output = STRPRINTF(
+                        AString output = STRPRINTF(
                                 "------ Items list of '%s' ------",
                                 pl_sd->status.name);
                         clif_displaymessage(s, output);
@@ -3888,7 +3888,7 @@ ATCE atcommand_character_item_list(Session *s, dumb_ptr<map_session_data> sd,
                     else
                         equipstr = MString();
 
-                    FString output;
+                    AString output;
                     if (sd->status.inventory[i].refine)
                         output = STRPRINTF("%d %s %+d (%s %+d, id: %d) %s",
                                  pl_sd->status.inventory[i].amount,
@@ -3897,13 +3897,13 @@ ATCE atcommand_character_item_list(Session *s, dumb_ptr<map_session_data> sd,
                                  item_data->jname,
                                  pl_sd->status.inventory[i].refine,
                                  pl_sd->status.inventory[i].nameid,
-                                 FString(equipstr));
+                                 AString(equipstr));
                     else
                         output = STRPRINTF("%d %s (%s, id: %d) %s",
                                  pl_sd->status.inventory[i].amount,
                                  item_data->name, item_data->jname,
                                  pl_sd->status.inventory[i].nameid,
-                                 FString(equipstr));
+                                 AString(equipstr));
                     clif_displaymessage(s, output);
 
                     MString voutput;
@@ -3938,7 +3938,7 @@ ATCE atcommand_character_item_list(Session *s, dumb_ptr<map_session_data> sd,
                         // replace trailing ", "
                         voutput.pop_back();
                         voutput.back() = ')';
-                        clif_displaymessage(s, FString(voutput));
+                        clif_displaymessage(s, AString(voutput));
                     }
                 }
             }
@@ -3946,7 +3946,7 @@ ATCE atcommand_character_item_list(Session *s, dumb_ptr<map_session_data> sd,
                 clif_displaymessage(s, "No item found on this player.");
             else
             {
-                FString output = STRPRINTF(
+                AString output = STRPRINTF(
                         "%d item(s) found in %d kind(s) of items.",
                         counter, count);
                 clif_displaymessage(s, output);
@@ -3999,12 +3999,12 @@ ATCE atcommand_character_storage_list(Session *s, dumb_ptr<map_session_data> sd,
                         count++;
                         if (count == 1)
                         {
-                            FString output = STRPRINTF(
+                            AString output = STRPRINTF(
                                     "------ Storage items list of '%s' ------",
                                     pl_sd->status.name);
                             clif_displaymessage(s, output);
                         }
-                        FString output;
+                        AString output;
                         if (stor->storage_[i].refine)
                             output = STRPRINTF("%d %s %+d (%s %+d, id: %d)",
                                      stor->storage_[i].amount,
@@ -4052,7 +4052,7 @@ ATCE atcommand_character_storage_list(Session *s, dumb_ptr<map_session_data> sd,
                             // replace last ", "
                             voutput.pop_back();
                             voutput.back() = ')';
-                            clif_displaymessage(s, FString(voutput));
+                            clif_displaymessage(s, AString(voutput));
                         }
                     }
                 }
@@ -4061,7 +4061,7 @@ ATCE atcommand_character_storage_list(Session *s, dumb_ptr<map_session_data> sd,
                             "No item found in the storage of this player.");
                 else
                 {
-                    FString output = STRPRINTF(
+                    AString output = STRPRINTF(
                             "%d item(s) found in %d kind(s) of items.",
                             counter, count);
                     clif_displaymessage(s, output);
@@ -4117,13 +4117,13 @@ ATCE atcommand_character_cart_list(Session *s, dumb_ptr<map_session_data> sd,
                     count++;
                     if (count == 1)
                     {
-                        FString output = STRPRINTF(
+                        AString output = STRPRINTF(
                                 "------ Cart items list of '%s' ------",
                                 pl_sd->status.name);
                         clif_displaymessage(s, output);
                     }
 
-                    FString output;
+                    AString output;
                     if (pl_sd->status.cart[i].refine)
                         output = STRPRINTF("%d %s %+d (%s %+d, id: %d)",
                                 pl_sd->status.cart[i].amount,
@@ -4170,7 +4170,7 @@ ATCE atcommand_character_cart_list(Session *s, dumb_ptr<map_session_data> sd,
                     {
                         voutput.pop_back();
                         voutput.back() = '0';
-                        clif_displaymessage(s, FString(voutput));
+                        clif_displaymessage(s, AString(voutput));
                     }
                 }
             }
@@ -4179,7 +4179,7 @@ ATCE atcommand_character_cart_list(Session *s, dumb_ptr<map_session_data> sd,
                         "No item found in the cart of this player.");
             else
             {
-                FString output = STRPRINTF("%d item(s) found in %d kind(s) of items.",
+                AString output = STRPRINTF("%d item(s) found in %d kind(s) of items.",
                          counter, count);
                 clif_displaymessage(s, output);
             }
@@ -4312,9 +4312,9 @@ ATCE atcommand_addwarp(Session *s, dumb_ptr<map_session_data> sd,
     if (!extract(message, record<' '>(&mapname, &x, &y)))
         return ATCE::USAGE;
 
-    FString w1 = STRPRINTF("%s,%d,%d", sd->mapname_, sd->bl_x, sd->bl_y);
-    FString w3 = STRPRINTF("%s%d%d%d%d", mapname, sd->bl_x, sd->bl_y, x, y);
-    FString w4 = STRPRINTF("1,1,%s.gat,%d,%d", mapname, x, y);
+    AString w1 = STRPRINTF("%s,%d,%d", sd->mapname_, sd->bl_x, sd->bl_y);
+    AString w3 = STRPRINTF("%s%d%d%d%d", mapname, sd->bl_x, sd->bl_y, x, y);
+    AString w4 = STRPRINTF("1,1,%s.gat,%d,%d", mapname, x, y);
 
     NpcName w3name = stringish<NpcName>(w3);
     int ret = npc_parse_warp(w1, ZString("warp"), w3name, w4);
@@ -4322,7 +4322,7 @@ ATCE atcommand_addwarp(Session *s, dumb_ptr<map_session_data> sd,
         // warp failed
         return ATCE::RANGE;
 
-    FString output = STRPRINTF("New warp NPC => %s", w3);
+    AString output = STRPRINTF("New warp NPC => %s", w3);
     clif_displaymessage(s, output);
 
     return ATCE::OKAY;
@@ -4689,7 +4689,7 @@ ATCE atcommand_magic_info(Session *s, dumb_ptr<map_session_data>,
     dumb_ptr<map_session_data> pl_sd = map_nick2sd(character);
     if (pl_sd)
     {
-        FString buf = STRPRINTF(
+        AString buf = STRPRINTF(
                 "`%s' has the following magic skills:",
                 character);
         clif_displaymessage(s, buf);
@@ -4788,7 +4788,7 @@ ATCE atcommand_tee(Session *, dumb_ptr<map_session_data> sd,
     data += sd->status.name.to__actual();
     data += " : ";
     data += message;
-    clif_message(sd, FString(data));
+    clif_message(sd, AString(data));
     return ATCE::OKAY;
 }
 
@@ -4845,7 +4845,7 @@ ATCE atcommand_jump_iterate(Session *s, dumb_ptr<map_session_data> sd,
         return ATCE::PERM;
     }
     pc_setpos(sd, pl_sd->bl_m->name_, pl_sd->bl_x, pl_sd->bl_y, BeingRemoveWhy::WARPED);
-    FString output = STRPRINTF("Jump to %s", pl_sd->status.name);
+    AString output = STRPRINTF("Jump to %s", pl_sd->status.name);
     clif_displaymessage(s, output);
 
     sd->followtarget = pl_sd->bl_id;
@@ -4896,7 +4896,7 @@ ATCE atcommand_skillpool_info(Session *s, dumb_ptr<map_session_data>,
         int pool_skills_nr = skill_pool(pl_sd, pool_skills);
         int i;
 
-        FString buf = STRPRINTF(
+        AString buf = STRPRINTF(
                 "Active skills %d out of %d for %s:",
                 pool_skills_nr, skill_pool_max(pl_sd), character);
         clif_displaymessage(s, buf);
@@ -4915,7 +4915,7 @@ ATCE atcommand_skillpool_info(Session *s, dumb_ptr<map_session_data>,
 
         for (i = 0; i < skill_pool_skills_size; ++i)
         {
-            const FString& name = skill_name(skill_pool_skills[i]);
+            const RString& name = skill_name(skill_pool_skills[i]);
             int lvl = pl_sd->status.skill[skill_pool_skills[i]].lv;
 
             if (lvl)
@@ -5042,7 +5042,7 @@ ATCE atcommand_ipcheck(Session *s, dumb_ptr<map_session_data>,
             // Is checking GM levels really needed here?
             if (ip == pl_sd->get_ip())
             {
-                FString output = STRPRINTF(
+                AString output = STRPRINTF(
                         "Name: %s | Location: %s %d %d",
                         pl_sd->status.name, pl_sd->mapname_,
                         pl_sd->bl_x, pl_sd->bl_y);
diff --git a/src/map/atcommand.hpp b/src/map/atcommand.hpp
index a18b035..c825976 100644
--- a/src/map/atcommand.hpp
+++ b/src/map/atcommand.hpp
@@ -15,7 +15,7 @@ bool atcommand_config_read(ZString cfgName);
 void log_atcommand(dumb_ptr<map_session_data> sd, ZString cmd);
 
 // only used by map.cpp
-extern FString gm_log;
+extern AString gm_log;
 
 void atcommand_config_write(ZString cfgName);
 
diff --git a/src/map/battle.cpp b/src/map/battle.cpp
index 35cef79..d1e79ef 100644
--- a/src/map/battle.cpp
+++ b/src/map/battle.cpp
@@ -2,7 +2,7 @@
 
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -2420,7 +2420,7 @@ bool battle_config_read(ZString cfgName)
         return false;
     }
 
-    FString line;
+    AString line;
     while (in.getline(line))
     {
 #define BATTLE_CONFIG_VAR(name) {{#name}, &battle_config.name}
@@ -2555,7 +2555,7 @@ bool battle_config_read(ZString cfgName)
                 goto continue_outer;
             }
 
-        PRINTF("WARNING: unknown battle conf key: %s\n", FString(w1));
+        PRINTF("WARNING: unknown battle conf key: %s\n", AString(w1));
         rv = false;
 
     continue_outer:
diff --git a/src/map/chrif.cpp b/src/map/chrif.cpp
index ab67b5c..c49a101 100644
--- a/src/map/chrif.cpp
+++ b/src/map/chrif.cpp
@@ -4,7 +4,7 @@
 
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -462,7 +462,7 @@ int chrif_char_ask_name_answer(Session *s)
     dumb_ptr<map_session_data> sd = map_id2sd(acc);
     if (acc >= 0 && sd != NULL)
     {
-        FString output;
+        AString output;
         if (RFIFOW(s, 32) == 1)   // player not found
             output = STRPRINTF("The player '%s' doesn't exist.",
                     player_name);
diff --git a/src/map/clif.cpp b/src/map/clif.cpp
index 61c47d9..3fc716d 100644
--- a/src/map/clif.cpp
+++ b/src/map/clif.cpp
@@ -6,7 +6,7 @@
 #include <cstring>
 #include <ctime>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -217,7 +217,7 @@ enum class ChatType
 };
 
 static
-FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type);
+AString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type);
 
 /*==========================================
  * clif_sendでSendWho::AREA*指定時用
@@ -3761,7 +3761,7 @@ void clif_parse_GlobalMessage(Session *s, dumb_ptr<map_session_data> sd)
 {
     nullpo_retv(sd);
 
-    FString mbuf = clif_validate_chat(sd, ChatType::Global);
+    AString mbuf = clif_validate_chat(sd, ChatType::Global);
     if (!mbuf)
     {
         clif_displaymessage(s, "Your message could not be sent.");
@@ -4017,7 +4017,7 @@ void clif_parse_Wis(Session *s, dumb_ptr<map_session_data> sd)
 
     nullpo_retv(sd);
 
-    FString mbuf = clif_validate_chat(sd, ChatType::Whisper);
+    AString mbuf = clif_validate_chat(sd, ChatType::Whisper);
     if (!mbuf)
     {
         clif_displaymessage(s, "Your message could not be sent.");
@@ -4628,7 +4628,7 @@ void clif_parse_PartyMessage(Session *s, dumb_ptr<map_session_data> sd)
 {
     nullpo_retv(sd);
 
-    FString mbuf = clif_validate_chat(sd, ChatType::Party);
+    AString mbuf = clif_validate_chat(sd, ChatType::Party);
     if (!mbuf)
     {
         clif_displaymessage(s, "Your message could not be sent.");
@@ -5294,15 +5294,15 @@ void WARN_MALFORMED_MSG(dumb_ptr<map_session_data> sd, const char *msg)
  * @return a dynamically allocated copy of the message, or empty string upon failure
  */
 static
-FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
+AString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
 {
-    nullpo_retr(FString(), sd);
+    nullpo_retr(AString(), sd);
     /*
      * Don't send chat in the period between the ban and the connection's
      * closure.
      */
     if (sd->auto_ban_info.in_progress)
-        return FString();
+        return AString();
 
     Session *s = sd->sess;
     size_t msg_len = RFIFOW(s, 2) - 4;
@@ -5326,14 +5326,14 @@ FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
     if (!msg_len)
     {
         WARN_MALFORMED_MSG(sd, "no message sent");
-        return FString();
+        return AString();
     }
 
     /* The client sent (or claims to have sent) an empty message. */
     if (msg_len == min_len)
     {
         WARN_MALFORMED_MSG(sd, "empty message");
-        return FString();
+        return AString();
     }
 
     /* The protocol specifies that the target must be 24 bytes long. */
@@ -5342,7 +5342,7 @@ FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
         /* Disallow malformed messages. */
         clif_setwaitclose(s);
         WARN_MALFORMED_MSG(sd, "illegal target name");
-        return FString();
+        return AString();
     }
 
     size_t pstart = 4;
@@ -5352,7 +5352,7 @@ FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
         pstart += 24;
         buf_len -= 24;
     }
-    FString pbuf = RFIFO_STRING(s, pstart, buf_len);
+    AString pbuf = RFIFO_STRING(s, pstart, buf_len);
 
     /*
      * The client attempted to exceed the maximum message length.
@@ -5364,7 +5364,7 @@ FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
     if (buf_len >= battle_config.chat_maxline)
     {
         WARN_MALFORMED_MSG(sd, "exceeded maximum message length");
-        return FString();
+        return AString();
     }
 
     if (type == ChatType::Global)
@@ -5375,7 +5375,7 @@ FString clif_validate_chat(dumb_ptr<map_session_data> sd, ChatType type)
             /* Disallow malformed/spoofed messages. */
             clif_setwaitclose(s);
             WARN_MALFORMED_MSG(sd, "spoofed name/invalid format");
-            return FString();
+            return AString();
         }
         /* Step beyond the separator. */
         XString xs = p.xslice_t(name_len + 3);
diff --git a/src/map/grfio.cpp b/src/map/grfio.cpp
index ff73c90..d89fe21 100644
--- a/src/map/grfio.cpp
+++ b/src/map/grfio.cpp
@@ -13,7 +13,8 @@
 #include <map>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/rstring.hpp"
+#include "../strings/astring.hpp"
 
 #include "../io/cxxstdio.hpp"
 #include "../io/read.hpp"
@@ -23,7 +24,7 @@
 #include "../poison.hpp"
 
 static
-std::map<MapName, FString> resnametable;
+std::map<MapName, RString> resnametable;
 
 bool load_resnametable(ZString filename)
 {
@@ -35,11 +36,11 @@ bool load_resnametable(ZString filename)
     }
 
     bool rv = true;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         MapName key;
-        FString value;
+        AString value;
         if (!extract(line,
                     record<'#'>(&key, &value)))
         {
@@ -47,6 +48,7 @@ bool load_resnametable(ZString filename)
             rv = false;
             continue;
         }
+        // TODO add "data/" here ...
         resnametable[key] = value;
     }
     return rv;
@@ -54,18 +56,21 @@ bool load_resnametable(ZString filename)
 
 /// Change *.gat to *.wlk
 static
-FString grfio_resnametable(MapName rname)
+RString grfio_resnametable(MapName rname)
 {
+    // TODO return an error instead of throwing an exception
     return resnametable.at(rname);
 }
 
 std::vector<uint8_t> grfio_reads(MapName rname)
 {
     MString lfname_;
+    // TODO ... instead of here
     lfname_ += "data/";
     lfname_ += grfio_resnametable(rname);
-    FString lfname = FString(lfname_);
+    AString lfname = AString(lfname_);
 
+    // TODO wrap this immediately
     int fd = open(lfname.c_str(), O_RDONLY);
     if (fd == -1)
     {
diff --git a/src/map/intif.cpp b/src/map/intif.cpp
index 7d699dd..e994bdb 100644
--- a/src/map/intif.cpp
+++ b/src/map/intif.cpp
@@ -3,7 +3,7 @@
 #include <cstdlib>
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -254,7 +254,7 @@ int intif_parse_WisMessage(Session *s)
     CharName to = stringish<CharName>(RFIFO_STRING<24>(s, 32));
 
     size_t len = RFIFOW(s, 2) - 56;
-    FString buf = RFIFO_STRING(s, 56, len);
+    AString buf = RFIFO_STRING(s, 56, len);
 
     if (battle_config.etc_log)
     {
@@ -313,7 +313,7 @@ void mapif_parse_WisToGM(Session *s)
 
     min_gm_level = RFIFOW(s, 28);
     CharName Wisp_name = stringish<CharName>(RFIFO_STRING<24>(s, 4));
-    FString message = RFIFO_STRING(s, 30, len);
+    AString message = RFIFO_STRING(s, 30, len);
     // information is sended to all online GM
     for (io::FD i : iter_fds())
     {
@@ -503,7 +503,7 @@ static
 void intif_parse_PartyMessage(Session *s)
 {
     size_t len = RFIFOW(s, 2) - 12;
-    FString buf = RFIFO_STRING(s, 12, len);
+    AString buf = RFIFO_STRING(s, 12, len);
     party_recv_message(RFIFOL(s, 4), RFIFOL(s, 8), buf);
 }
 
@@ -542,7 +542,7 @@ int intif_parse(Session *s)
     {
         case 0x3800:
         {
-            FString mes = RFIFO_STRING(s, 4, packet_len - 4);
+            AString mes = RFIFO_STRING(s, 4, packet_len - 4);
             clif_GMmessage(NULL, mes, 0);
         }
             break;
diff --git a/src/map/itemdb.cpp b/src/map/itemdb.cpp
index bcef583..ba225bd 100644
--- a/src/map/itemdb.cpp
+++ b/src/map/itemdb.cpp
@@ -3,7 +3,7 @@
 #include <cstdlib>
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -161,7 +161,7 @@ bool itemdb_readdb(ZString filename)
 
         lines = 0;
 
-        FString line;
+        AString line;
         while (in.getline(line))
         {
             lines++;
diff --git a/src/map/magic-expr.cpp b/src/map/magic-expr.cpp
index 655da1b..7343e50 100644
--- a/src/map/magic-expr.cpp
+++ b/src/map/magic-expr.cpp
@@ -6,7 +6,7 @@
 #include <cmath>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/vstring.hpp"
 
@@ -93,7 +93,7 @@ void magic_clear_var(val_t *v)
 }
 
 static
-FString show_entity(dumb_ptr<block_list> entity)
+AString show_entity(dumb_ptr<block_list> entity)
 {
     switch (entity->bl_type)
     {
@@ -126,7 +126,7 @@ void stringify(val_t *v, int within_op)
         {"north"}, {"north-east"},
         {"east"}, {"south-east"},
     }};
-    FString buf;
+    AString buf;
 
     switch (v->ty)
     {
@@ -287,7 +287,7 @@ int fun_add(dumb_ptr<env_t>, val_t *result, const_array<val_t> args)
         MString m;
         m += ARGSTR(0);
         m += ARGSTR(1);
-        RESULTSTR = dumb_string::copys(FString(m));
+        RESULTSTR = dumb_string::copys(AString(m));
         result->ty = TYPE::STRING;
     }
     return 0;
@@ -1677,7 +1677,7 @@ int magic_eval_int(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr)
     return result.v.v_int;
 }
 
-FString magic_eval_str(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr)
+AString magic_eval_str(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr)
 {
     val_t result;
     magic_eval(env, &result, expr);
diff --git a/src/map/magic-expr.hpp b/src/map/magic-expr.hpp
index 7601bef..0fdc435 100644
--- a/src/map/magic-expr.hpp
+++ b/src/map/magic-expr.hpp
@@ -61,7 +61,7 @@ int magic_eval_int(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr);
 /**
  * Evaluates an expression and coerces the result into a string
  */
-FString magic_eval_str(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr);
+AString magic_eval_str(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr);
 
 dumb_ptr<expr_t> magic_new_expr(EXPR ty);
 
diff --git a/src/map/magic-interpreter-base.cpp b/src/map/magic-interpreter-base.cpp
index 0ba145a..f1878a0 100644
--- a/src/map/magic-interpreter-base.cpp
+++ b/src/map/magic-interpreter-base.cpp
@@ -3,7 +3,7 @@
 #include "magic-interpreter-aux.hpp"
 #include "magic-interpreter.hpp"
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/xstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -68,13 +68,13 @@ void set_spell SETTER(dumb_ptr<spell_t>, TYPE::SPELL, v_spell)
 magic_conf_t magic_conf;        /* Global magic conf */
 env_t magic_default_env = { &magic_conf, NULL };
 
-FString magic_find_invocation(XString spellname)
+AString magic_find_invocation(XString spellname)
 {
     auto it = magic_conf.spells_by_name.find(spellname);
     if (it != magic_conf.spells_by_name.end())
         return it->second->invocation;
 
-    return FString();
+    return AString();
 }
 
 dumb_ptr<spell_t> magic_find_spell(XString invocation)
@@ -90,14 +90,14 @@ dumb_ptr<spell_t> magic_find_spell(XString invocation)
 /* Spell anchors */
 /* -------------------------------------------------------------------------------- */
 
-FString magic_find_anchor_invocation(XString anchor_name)
+AString magic_find_anchor_invocation(XString anchor_name)
 {
     auto it = magic_conf.anchors_by_name.find(anchor_name);
 
     if (it != magic_conf.anchors_by_name.end())
         return it->second->invocation;
 
-    return FString();
+    return AString();
 }
 
 dumb_ptr<teleport_anchor_t> magic_find_anchor(XString name)
diff --git a/src/map/magic-interpreter-parser.ypp b/src/map/magic-interpreter-parser.ypp
index a86f1c8..3ec1bdd 100644
--- a/src/map/magic-interpreter-parser.ypp
+++ b/src/map/magic-interpreter-parser.ypp
@@ -3,7 +3,7 @@
 #include "magic-interpreter.hpp"
 
 extern
-FString current_magic_filename;
+AString current_magic_filename;
 } // %code requires
 
 %code
@@ -13,7 +13,8 @@ FString current_magic_filename;
 #include <cassert>
 #include <cstdarg> // exception to "no va_list" rule, even after cxxstdio
 
-#include "../strings/fstring.hpp"
+#include "../strings/rstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -23,7 +24,7 @@ FString current_magic_filename;
 #include "itemdb.hpp"
 #include "magic-expr.hpp"
 
-FString current_magic_filename;
+AString current_magic_filename;
 
 // can't use src/warnings.hpp in generated code
 #pragma GCC diagnostic warning "-Wall"
@@ -37,13 +38,13 @@ static
 size_t intern_id(ZString id_name);
 
 static
-dumb_ptr<expr_t> fun_expr(FString name, const_array<dumb_ptr<expr_t>> argv, int line, int column);
+dumb_ptr<expr_t> fun_expr(AString name, const_array<dumb_ptr<expr_t>> argv, int line, int column);
 
 static
 dumb_ptr<expr_t> dot_expr(dumb_ptr<expr_t> lhs, int id);
 
 static
-void BIN_EXPR(dumb_ptr<expr_t>& x, FString name, dumb_ptr<expr_t> arg1, dumb_ptr<expr_t> arg2, int line, int column)
+void BIN_EXPR(dumb_ptr<expr_t>& x, AString name, dumb_ptr<expr_t> arg1, dumb_ptr<expr_t> arg2, int line, int column)
 {
     dumb_ptr<expr_t> e[2];
     e[0] = arg1;
@@ -82,7 +83,7 @@ static
 void add_teleport_anchor(dumb_ptr<teleport_anchor_t> anchor, int line_nr);
 
 static
-dumb_ptr<effect_t> op_effect(FString name, const_array<dumb_ptr<expr_t>> argv, int line, int column);
+dumb_ptr<effect_t> op_effect(AString name, const_array<dumb_ptr<expr_t>> argv, int line, int column);
 
 // in magic-interpreter-lexer.cpp
 int magic_frontend_lex(void);
@@ -94,10 +95,10 @@ static
 dumb_ptr<effect_t> call_proc(ZString name, dumb_ptr<std::vector<dumb_ptr<expr_t>>> argvp, int line_nr, int column);
 
 static
-void bind_constant(FString name, val_t *val, int line_nr);
+void bind_constant(RString name, val_t *val, int line_nr);
 
 static
-val_t *find_constant(FString name);
+val_t *find_constant(RString name);
 
 } // %code
 
@@ -1182,7 +1183,7 @@ dumb_ptr<expr_t> dot_expr(dumb_ptr<expr_t> expr, int id)
     return retval;
 }
 
-dumb_ptr<expr_t> fun_expr(FString name, const_array<dumb_ptr<expr_t>> argv, int line, int column)
+dumb_ptr<expr_t> fun_expr(AString name, const_array<dumb_ptr<expr_t>> argv, int line, int column)
 {
     dumb_ptr<expr_t> expr;
     fun_t *fun = magic_get_fun(name);
@@ -1293,7 +1294,7 @@ dumb_ptr<effect_t> set_effect_continuation(dumb_ptr<effect_t> src, dumb_ptr<effe
     return retval;
 }
 
-dumb_ptr<effect_t> op_effect(FString name, const_array<dumb_ptr<expr_t>> argv, int line, int column)
+dumb_ptr<effect_t> op_effect(AString name, const_array<dumb_ptr<expr_t>> argv, int line, int column)
 {
     dumb_ptr<effect_t> effect;
     op_t *op = magic_get_op(name);
@@ -1325,7 +1326,7 @@ dumb_ptr<effect_t> op_effect(FString name, const_array<dumb_ptr<expr_t>> argv, i
 }
 
 
-std::map<FString, proc_t> procs;
+std::map<RString, proc_t> procs;
 
 // I think this was a memory leak (or undefined behavior)
 void install_proc(dumb_ptr<proc_t> proc)
@@ -1358,9 +1359,9 @@ dumb_ptr<effect_t> call_proc(ZString name, dumb_ptr<std::vector<dumb_ptr<expr_t>
     return retval;
 }
 
-std::map<FString, val_t> const_defm;
+std::map<RString, val_t> const_defm;
 
-void bind_constant(FString name, val_t *val, int line_nr)
+void bind_constant(RString name, val_t *val, int line_nr)
 {
     if (!const_defm.insert({name, *val}).second)
     {
@@ -1368,7 +1369,7 @@ void bind_constant(FString name, val_t *val, int line_nr)
     }
 }
 
-val_t *find_constant(FString name)
+val_t *find_constant(RString name)
 {
     auto it = const_defm.find(name);
     if (it != const_defm.end())
diff --git a/src/map/magic-interpreter.hpp b/src/map/magic-interpreter.hpp
index 19f8574..7e42499 100644
--- a/src/map/magic-interpreter.hpp
+++ b/src/map/magic-interpreter.hpp
@@ -6,7 +6,7 @@
 # include <cassert>
 
 # include "../strings/fwd.hpp"
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
 
 # include "magic.hpp"
 # include "map.hpp"
@@ -244,8 +244,8 @@ struct letdef_t
 
 struct spell_t
 {
-    FString name;
-    FString invocation;
+    RString name;
+    RString invocation;
     SPELL_FLAG flags;
     int arg;
     SPELLARG spellarg_ty;
@@ -261,8 +261,8 @@ struct spell_t
 
 struct teleport_anchor_t
 {
-    FString name;
-    FString invocation;
+    RString name;
+    RString invocation;
     dumb_ptr<expr_t> location;
 };
 
@@ -274,15 +274,15 @@ struct magic_conf_t
 {
     struct mcvar
     {
-        FString name;
+        RString name;
         val_t val;
     };
     // This should probably be done by a dedicated "intern pool" class
     std::vector<mcvar> varv;
 
-    std::map<FString, dumb_ptr<spell_t>> spells_by_name, spells_by_invocation;
+    std::map<RString, dumb_ptr<spell_t>> spells_by_name, spells_by_invocation;
 
-    std::map<FString, dumb_ptr<teleport_anchor_t>> anchors_by_name, anchors_by_invocation;
+    std::map<RString, dumb_ptr<teleport_anchor_t>> anchors_by_name, anchors_by_invocation;
 };
 
 /* Execution environment */
@@ -434,7 +434,7 @@ struct args_rec_t
 
 struct proc_t
 {
-    FString name;
+    RString name;
     std::vector<int> argv;
     dumb_ptr<effect_t> body;
 
diff --git a/src/map/magic.hpp b/src/map/magic.hpp
index 5d4e517..1fabd6f 100644
--- a/src/map/magic.hpp
+++ b/src/map/magic.hpp
@@ -46,14 +46,14 @@ void spell_effect_report_termination(int invocation, int bl_id,
  *
  * Returns empty string if not found
  */
-FString magic_find_invocation(XString spellname);
+AString magic_find_invocation(XString spellname);
 
 /**
  * Identifies the invocation used to denote a teleport location
  *
  * Returns empty string if not found
  */
-FString magic_find_anchor_invocation(XString teleport_location);
+AString magic_find_anchor_invocation(XString teleport_location);
 
 /**
  * Execute a spell invocation and sets up timers to finish
diff --git a/src/map/map.cpp b/src/map/map.cpp
index 8a1d8eb..caab5b4 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -10,7 +10,7 @@
 #include <cstdlib>
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 #include "../strings/vstring.hpp"
@@ -75,7 +75,7 @@ int first_free_object_id = 0, last_object_id = 0;
 interval_t autosave_time = DEFAULT_AUTOSAVE_INTERVAL;
 int save_settings = 0xFFFF;
 
-FString motd_txt = "conf/motd.txt";
+AString motd_txt = "conf/motd.txt";
 
 CharName wisp_server_name = stringish<CharName>("Server");   // can be modified in char-server configuration file
 
@@ -1351,7 +1351,7 @@ constexpr int LOGFILE_SECONDS_PER_CHUNK_SHIFT = 10;
 static
 std::unique_ptr<io::AppendFile> map_logfile;
 static
-FString map_logfile_name;
+AString map_logfile_name;
 static
 long map_logfile_index;
 
@@ -1360,7 +1360,7 @@ void map_close_logfile(void)
 {
     if (map_logfile)
     {
-        FString filename = STRPRINTF("%s.%ld", map_logfile_name, map_logfile_index);
+        AString filename = STRPRINTF("%s.%ld", map_logfile_name, map_logfile_index);
         const char *args[] =
         {
             "gzip",
@@ -1386,7 +1386,7 @@ void map_start_logfile(long index)
 {
     map_logfile_index = index;
 
-    FString filename_buf = STRPRINTF(
+    AString filename_buf = STRPRINTF(
             "%s.%ld",
             map_logfile_name,
             map_logfile_index);
@@ -1399,7 +1399,7 @@ void map_start_logfile(long index)
 }
 
 static
-void map_set_logfile(FString filename)
+void map_set_logfile(AString filename)
 {
     struct timeval tv;
 
@@ -1445,7 +1445,7 @@ bool map_config_read(ZString cfgName)
     }
 
     bool rv = true;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         if (is_comment(line))
@@ -1663,7 +1663,7 @@ bool map_confs(XString key, ZString value)
         return load_resnametable(value);
     if (key == "const_db")
         return read_constdb(value);
-    PRINTF("unknown map conf key: %s\n", FString(key));
+    PRINTF("unknown map conf key: %s\n", AString(key));
     return false;
 }
 
diff --git a/src/map/map.hpp b/src/map/map.hpp
index 897c619..092fd80 100644
--- a/src/map/map.hpp
+++ b/src/map/map.hpp
@@ -9,7 +9,8 @@
 # include <list>
 
 # include "../strings/fwd.hpp"
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
+# include "../strings/astring.hpp"
 # include "../strings/vstring.hpp"
 
 # include "../io/cxxstdio.hpp"
@@ -193,7 +194,7 @@ struct map_session_data : block_list, SessionData
     // but one should probably be replaced with a ScriptPointer ???
     const ScriptBuffer *npc_script, *npc_scriptroot;
     std::vector<struct script_data> npc_stackbuf;
-    FString npc_str;
+    RString npc_str;
     struct
     {
         unsigned storage:1;
@@ -267,8 +268,8 @@ struct map_session_data : block_list, SessionData
     // Not anymore! Well, sort of.
     DMap<SIR, int> regm;
     // can't be DMap because we want predictable .c_str()s
-    // This could change once FString ensures CoW.
-    Map<SIR, FString> regstrm;
+    // TODO this can change now
+    Map<SIR, RString> regstrm;
 
     earray<struct status_change, StatusChange, StatusChange::MAX_STATUSCHANGE> sc_data;
     short sc_count;
@@ -302,7 +303,7 @@ struct map_session_data : block_list, SessionData
     TimeT chat_repeat_reset_due;
     int chat_lines_in;
     int chat_total_repeats;
-    FString chat_lastmsg;
+    RString chat_lastmsg;
 
     tick_t flood_rates[0x220];
     TimeT packet_flood_reset_due;
@@ -347,7 +348,7 @@ struct npc_data : block_list
     Option option;
     short flag;
 
-    std::list<FString> eventqueuel;
+    std::list<RString> eventqueuel;
     Timer eventtimer[MAX_EVENTTIMER];
     short arenaflag;
 
@@ -414,7 +415,7 @@ public:
 class npc_data_message : public npc_data
 {
 public:
-    FString message;
+    RString message;
 };
 
 constexpr int MOB_XP_BONUS_BASE = 1024;
@@ -574,7 +575,7 @@ struct flooritem_data : block_list
 extern interval_t autosave_time;
 extern int save_settings;
 
-extern FString motd_txt;
+extern AString motd_txt;
 
 extern CharName wisp_server_name;
 
diff --git a/src/map/mob.cpp b/src/map/mob.cpp
index 7a73df5..2a06cf7 100644
--- a/src/map/mob.cpp
+++ b/src/map/mob.cpp
@@ -8,7 +8,7 @@
 
 #include <algorithm>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/xstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -3420,7 +3420,7 @@ bool mob_readdb(ZString filename)
             PRINTF("Unable to read mob db: %s\n", filename);
             return false;
         }
-        FString line;
+        AString line;
         while (in.getline(line))
         {
             int mob_class;
@@ -3631,7 +3631,7 @@ bool mob_readskilldb(ZString filename)
             PRINTF("can't read %s\n", filename);
             return false;
         }
-        FString line;
+        AString line;
         while (in.getline(line))
         {
             int mob_id;
diff --git a/src/map/npc.cpp b/src/map/npc.cpp
index 4a116b2..788d785 100644
--- a/src/map/npc.cpp
+++ b/src/map/npc.cpp
@@ -8,7 +8,7 @@
 #include <list>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -34,7 +34,7 @@
 #include "../poison.hpp"
 
 static
-std::list<FString> npc_srcs;
+std::list<AString> npc_srcs;
 
 static
 int npc_id = START_NPC_NUM;
@@ -903,7 +903,7 @@ void npc_clearsrcfile(void)
  * 読み込むnpcファイルの追加
  *------------------------------------------
  */
-void npc_addsrcfile(FString name)
+void npc_addsrcfile(AString name)
 {
     if (name == "clear")
     {
@@ -918,7 +918,7 @@ void npc_addsrcfile(FString name)
  * 読み込むnpcファイルの削除
  *------------------------------------------
  */
-void npc_delsrcfile(FString name)
+void npc_delsrcfile(XString name)
 {
     if (name == "all")
     {
@@ -1209,7 +1209,7 @@ int npc_parse_script(XString w1, XString w2, NpcName w3, ZString w4,
             if (it != srcbuf.rend() && *it == '}')
                 break;
 
-            FString line;
+            AString line;
             if (!fp.getline(line))
                 // eof
                 break;
@@ -1226,7 +1226,7 @@ int npc_parse_script(XString w1, XString w2, NpcName w3, ZString w4,
                 srcbuf += line;
             srcbuf += '\n';
         }
-        script = parse_script(FString(srcbuf), startline);
+        script = parse_script(AString(srcbuf), startline);
         if (script == NULL)
             // script parse error?
             return 1;
@@ -1404,7 +1404,7 @@ int npc_parse_function(XString, XString, XString w3, ZString,
         if (it != srcbuf.rend() && *it == '}')
             break;
 
-        FString line;
+        AString line;
         if (!fp.getline(line))
             break;
         (*lines)++;
@@ -1417,7 +1417,7 @@ int npc_parse_function(XString, XString, XString w3, ZString,
             srcbuf += line;
         srcbuf += '\n';
     }
-    std::unique_ptr<const ScriptBuffer> script = parse_script(FString(srcbuf), startline);
+    std::unique_ptr<const ScriptBuffer> script = parse_script(AString(srcbuf), startline);
     if (script == NULL)
     {
         // script parse error?
@@ -1636,7 +1636,7 @@ int npc_parse_mapflag(XString w1, XString, XString w3, ZString w4)
 }
 
 dumb_ptr<npc_data> npc_spawn_text(map_local *m, int x, int y,
-        int npc_class, NpcName name, FString message)
+        int npc_class, NpcName name, AString message)
 {
     dumb_ptr<npc_data_message> retval;
     retval.new_();
@@ -1678,7 +1678,7 @@ void npc_free_internal(dumb_ptr<npc_data> nd_)
     else if (nd_->npc_subtype == NpcSubtype::MESSAGE)
     {
         dumb_ptr<npc_data_message> nd = nd_->is_message();
-        nd->message = FString();
+        nd->message = AString();
     }
     nd_.delete_();
 }
@@ -1722,7 +1722,7 @@ bool do_init_npc(void)
 
     for (; !npc_srcs.empty(); npc_srcs.pop_front())
     {
-        FString nsl = npc_srcs.front();
+        AString nsl = npc_srcs.front();
         io::ReadFile fp(nsl);
         if (!fp.is_open())
         {
@@ -1733,7 +1733,7 @@ bool do_init_npc(void)
         PRINTF("\rLoading NPCs [%d]: %-54s", npc_id - START_NPC_NUM,
                 nsl);
         int lines = 0;
-        FString zline;
+        AString zline;
         while (fp.getline(zline))
         {
             XString w1, w2, w3, w4x;
diff --git a/src/map/npc.hpp b/src/map/npc.hpp
index 17eea04..4d4cef1 100644
--- a/src/map/npc.hpp
+++ b/src/map/npc.hpp
@@ -39,15 +39,15 @@ int npc_get_new_npc_id(void);
  * \param message The message to speak.  If message is NULL, the NPC will not do anything at all.
  */
 dumb_ptr<npc_data> npc_spawn_text(map_local *m, int x, int y,
-        int class_, NpcName name, FString message);
+        int class_, NpcName name, AString message);
 
 /**
  * Uninstalls and frees an NPC
  */
 void npc_free(dumb_ptr<npc_data> npc);
 
-void npc_addsrcfile(FString);
-void npc_delsrcfile(FString);
+void npc_addsrcfile(AString);
+void npc_delsrcfile(XString);
 bool do_init_npc(void);
 int npc_event_do_oninit(void);
 
diff --git a/src/map/pc.cpp b/src/map/pc.cpp
index 8d242ae..c9588bb 100644
--- a/src/map/pc.cpp
+++ b/src/map/pc.cpp
@@ -4,7 +4,8 @@
 #include <cstdlib>
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/rstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -751,7 +752,7 @@ int pc_authok(int id, int login_id2, TimeT connect_until_time,
     sd->chat_reset_due = TimeT();
     sd->chat_lines_in = sd->chat_total_repeats = 0;
     sd->chat_repeat_reset_due = TimeT();
-    sd->chat_lastmsg = FString();
+    sd->chat_lastmsg = RString();
 
     for (tick_t& t : sd->flood_rates)
         t = tick_t();
@@ -780,7 +781,7 @@ void pc_show_motd(dumb_ptr<map_session_data> sd)
     io::ReadFile in(motd_txt);
     if (in.is_open())
     {
-        FString buf;
+        AString buf;
         while (in.getline(buf))
         {
             clif_displaymessage(sd->sess, buf);
@@ -3094,7 +3095,7 @@ int pc_gainexp_reason(dumb_ptr<map_session_data> sd, int base_exp, int job_exp,
 
     if (battle_config.disp_experience)
     {
-        FString output = STRPRINTF(
+        AString output = STRPRINTF(
                 "Experienced Gained Base:%d Job:%d",
                 base_exp, job_exp);
         clif_displaymessage(sd->sess, output);
@@ -4123,7 +4124,7 @@ ZString pc_readregstr(dumb_ptr<map_session_data> sd, SIR reg)
 {
     nullpo_retr(ZString(), sd);
 
-    FString *s = sd->regstrm.search(reg);
+    RString *s = sd->regstrm.search(reg);
     if (s)
         return *s;
 
@@ -4134,7 +4135,7 @@ ZString pc_readregstr(dumb_ptr<map_session_data> sd, SIR reg)
  * script用文字列変数の値を設定
  *------------------------------------------
  */
-void pc_setregstr(dumb_ptr<map_session_data> sd, SIR reg, FString str)
+void pc_setregstr(dumb_ptr<map_session_data> sd, SIR reg, RString str)
 {
     nullpo_retv(sd);
 
diff --git a/src/map/pc.hpp b/src/map/pc.hpp
index 48ba8f3..be66cc4 100644
--- a/src/map/pc.hpp
+++ b/src/map/pc.hpp
@@ -123,7 +123,7 @@ int pc_setparam(dumb_ptr<map_session_data>, SP, int);
 int pc_readreg(dumb_ptr<map_session_data>, SIR);
 void pc_setreg(dumb_ptr<map_session_data>, SIR, int);
 ZString pc_readregstr(dumb_ptr<map_session_data> sd, SIR reg);
-void pc_setregstr(dumb_ptr<map_session_data> sd, SIR reg, FString str);
+void pc_setregstr(dumb_ptr<map_session_data> sd, SIR reg, RString str);
 int pc_readglobalreg(dumb_ptr<map_session_data>, VarName );
 int pc_setglobalreg(dumb_ptr<map_session_data>, VarName , int);
 int pc_readaccountreg(dumb_ptr<map_session_data>, VarName );
diff --git a/src/map/script.cpp b/src/map/script.cpp
index c154182..36ceb8c 100644
--- a/src/map/script.cpp
+++ b/src/map/script.cpp
@@ -8,7 +8,8 @@
 #include <ctime>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/rstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -49,27 +50,27 @@ constexpr bool DEBUG_RUN = false;
 struct str_data_t
 {
     ByteCode type;
-    FString strs;
+    RString strs;
     int backpatch;
     int label_;
     int val;
 };
 static
-Map<FString, str_data_t> str_datam;
+Map<RString, str_data_t> str_datam;
 static
 str_data_t LABEL_NEXTLINE_;
 
 static
 DMap<SIR, int> mapreg_db;
 static
-Map<SIR, FString> mapregstr_db;
+Map<SIR, RString> mapregstr_db;
 static
 int mapreg_dirty = -1;
-FString mapreg_txt = "save/mapreg.txt";
+AString mapreg_txt = "save/mapreg.txt";
 constexpr std::chrono::milliseconds MAPREG_AUTOSAVE_INTERVAL = std::chrono::seconds(10);
 
 Map<ScriptLabel, int> scriptlabel_db;
-UPMap<FString, const ScriptBuffer> userfunc_db;
+UPMap<RString, const ScriptBuffer> userfunc_db;
 
 static
 const char *pos_str[11] =
@@ -157,7 +158,7 @@ str_data_t *add_strp(XString p)
     if (str_data_t *rv = search_strp(p))
         return rv;
 
-    FString p2 = p;
+    RString p2 = p;
     str_data_t *datum = str_datam.init(p2);
     datum->type = ByteCode::NOP;
     datum->strs = p2;
@@ -699,13 +700,13 @@ bool read_constdb(ZString filename)
     }
 
     bool rv = true;
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         if (is_comment(line))
             continue;
 
-        FString name;
+        AString name;
         int val;
         int type = 0; // if not provided
         // TODO get rid of SSCANF - this is the last serious use
@@ -908,7 +909,7 @@ void get_val(ScriptState *st, struct script_data *data)
             }
             else if (prefix == '$')
             {
-                FString *s = mapregstr_db.search(data->u.reg);
+                RString *s = mapregstr_db.search(data->u.reg);
                 data->u.str = s ? dumb_string::fake(*s) : dumb_string();
             }
             else
@@ -1059,7 +1060,7 @@ dumb_string conv_str(ScriptState *st, struct script_data *data)
     assert (data->type != ByteCode::RETINFO);
     if (data->type == ByteCode::INT)
     {
-        FString buf = STRPRINTF("%d", data->u.numi);
+        AString buf = STRPRINTF("%d", data->u.numi);
         data->type = ByteCode::STR;
         data->u.str = dumb_string::copys(buf);
     }
@@ -1340,7 +1341,7 @@ void builtin_menu(ScriptState *st)
             buf += ':';
         }
 
-        clif_scriptmenu(script_rid2sd(st), st->oid, FString(buf));
+        clif_scriptmenu(script_rid2sd(st), st->oid, AString(buf));
     }
     else
     {
@@ -2233,7 +2234,7 @@ void builtin_getequipname(ScriptState *st)
     dumb_ptr<map_session_data> sd;
     struct item_data *item;
 
-    FString buf;
+    AString buf;
 
     sd = script_rid2sd(st);
     num = conv_num(st, &AARGO2(2));
@@ -3572,7 +3573,7 @@ void builtin_getspellinvocation(ScriptState *st)
 {
     dumb_string name = conv_str(st, &AARGO2(2));
 
-    FString invocation = magic_find_invocation(name.str());
+    AString invocation = magic_find_invocation(name.str());
     if (!invocation)
         invocation = "...";
 
@@ -3938,7 +3939,7 @@ void builtin_npctalk(ScriptState *st)
         message += nd->name;
         message += " : ";
         message += ZString(str);
-        clif_message(nd, FString(message));
+        clif_message(nd, AString(message));
     }
 }
 
@@ -4275,7 +4276,7 @@ void op_add(ScriptState *st)
         if (back.type == ByteCode::STR)
             back.u.str.delete_();
         back1.type = ByteCode::STR;
-        back1.u.str = dumb_string::copys(FString(buf));
+        back1.u.str = dumb_string::copys(AString(buf));
     }
 }
 
@@ -4921,7 +4922,7 @@ void script_load_mapreg(void)
     if (!in.is_open())
         return;
 
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         XString buf1, buf2;
@@ -4952,7 +4953,7 @@ void script_load_mapreg(void)
         else
         {
         borken:
-            PRINTF("%s: %s broken data !\n", mapreg_txt, FString(buf1));
+            PRINTF("%s: %s broken data !\n", mapreg_txt, AString(buf1));
             continue;
         }
     }
diff --git a/src/map/script.hpp b/src/map/script.hpp
index ec52f65..22a079b 100644
--- a/src/map/script.hpp
+++ b/src/map/script.hpp
@@ -6,7 +6,8 @@
 
 # include <vector>
 
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
+# include "../strings/astring.hpp"
 # include "../strings/zstring.hpp"
 
 # include "../common/db.hpp"
@@ -157,12 +158,12 @@ struct ScriptLabel;
 extern
 Map<ScriptLabel, int> scriptlabel_db;
 extern
-UPMap<FString, const ScriptBuffer> userfunc_db;
+UPMap<RString, const ScriptBuffer> userfunc_db;
 
 void do_init_script(void);
 void do_final_script(void);
 
-extern FString mapreg_txt;
+extern AString mapreg_txt;
 
 extern int script_errors;
 
diff --git a/src/map/skill.cpp b/src/map/skill.cpp
index 2253d9d..0222202 100644
--- a/src/map/skill.cpp
+++ b/src/map/skill.cpp
@@ -6,7 +6,7 @@
 #include <ctime>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/rstring.hpp"
 #include "../strings/xstring.hpp"
 
 #include "../io/cxxstdio.hpp"
@@ -1169,7 +1169,7 @@ SP scan_stat(XString statname)
     if (statname == "none")
         return SP::ZERO;
 
-    FPRINTF(stderr, "Unknown stat `%s'\n", FString(statname));
+    FPRINTF(stderr, "Unknown stat `%s'\n", AString(statname));
     return SP::ZERO;
 }
 
@@ -1183,7 +1183,7 @@ bool skill_readdb(ZString filename)
     }
 
     bool rv = true;
-    FString line_;
+    AString line_;
     while (in.getline(line_))
     {
         // is_comment only works for whole-line comments
@@ -1267,7 +1267,7 @@ bool skill_readdb(ZString filename)
                 c = ' ';
 
         skill_db[i] = skdb;
-        skill_lookup_by_id(i).desc = FString(tmp);
+        skill_lookup_by_id(i).desc = RString(tmp);
     }
     PRINTF("read %s done\n", filename);
 
diff --git a/src/map/skill.hpp b/src/map/skill.hpp
index 5f29443..e8f36ab 100644
--- a/src/map/skill.hpp
+++ b/src/map/skill.hpp
@@ -5,7 +5,8 @@
 # include "skill-pools.hpp"
 
 # include "../strings/fwd.hpp"
-# include "../strings/fstring.hpp"
+# include "../strings/rstring.hpp"
+# include "../strings/astring.hpp"
 
 # include "map.hpp"
 
@@ -39,11 +40,11 @@ earray<skill_db_, SkillID, SkillID::MAX_SKILL_DB> skill_db;
 struct skill_name_db
 {
     SkillID id;                    // skill id
-    FString name;                 // search strings
-    FString desc;                 // description that shows up for searches
+    RString name;                 // search strings
+    RString desc;                 // description that shows up for searches
 
     // this makes const char(&)[] not decay into const char * in {}
-    skill_name_db(SkillID i, FString n, FString d)
+    skill_name_db(SkillID i, RString n, RString d)
     : id(i), name(n), desc(d)
     {}
 };
@@ -129,7 +130,7 @@ bool skill_pool_is_activated(dumb_ptr<map_session_data> sd, SkillID skill);
 int skill_pool_deactivate(dumb_ptr<map_session_data> sd, SkillID skill);
 // Yield configurable skill name
 inline
-const FString& skill_name(SkillID skill)
+const RString& skill_name(SkillID skill)
 {
     return skill_lookup_by_id(skill).desc;
 }
diff --git a/src/map/tmw.cpp b/src/map/tmw.cpp
index 7e661bb..72cfa2b 100644
--- a/src/map/tmw.cpp
+++ b/src/map/tmw.cpp
@@ -3,7 +3,7 @@
 #include <cctype>
 #include <cstring>
 
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -95,16 +95,16 @@ void tmw_AutoBan(dumb_ptr<map_session_data> sd, ZString reason, int length)
 
     sd->auto_ban_info.in_progress = 1;
 
-    FString hack_msg = STRPRINTF("[GM] %s has been autobanned for %s spam",
+    AString hack_msg = STRPRINTF("[GM] %s has been autobanned for %s spam",
             sd->status.name,
             reason);
     tmw_GmHackMsg(hack_msg);
 
-    FString fake_command = STRPRINTF("@autoban %s %dh (%s spam)",
+    AString fake_command = STRPRINTF("@autoban %s %dh (%s spam)",
             sd->status.name, length, reason);
     log_atcommand(sd, fake_command);
 
-    FString anotherbuf = STRPRINTF("You have been banned for %s spamming. Please do not spam.",
+    AString anotherbuf = STRPRINTF("You have been banned for %s spamming. Please do not spam.",
             reason);
 
     clif_displaymessage(sd->sess, anotherbuf);
diff --git a/src/monitor/main.cpp b/src/monitor/main.cpp
index 352b375..e59be71 100644
--- a/src/monitor/main.cpp
+++ b/src/monitor/main.cpp
@@ -15,7 +15,7 @@
 #include <csignal>
 
 #include "../strings/mstring.hpp"
-#include "../strings/fstring.hpp"
+#include "../strings/astring.hpp"
 #include "../strings/zstring.hpp"
 #include "../strings/xstring.hpp"
 
@@ -36,26 +36,26 @@
 
 // initialiized to $HOME/tmwserver
 static
-FString workdir;
+AString workdir;
 //the rest are relative to workdir
 static
-FString login_server = LOGIN_SERVER;
+AString login_server = LOGIN_SERVER;
 static
-FString map_server = MAP_SERVER;
+AString map_server = MAP_SERVER;
 static
-FString char_server = CHAR_SERVER;
+AString char_server = CHAR_SERVER;
 
 static
 pid_t pid_login, pid_map, pid_char;
 
 static
-FString make_path(XString base, XString path)
+AString make_path(XString base, XString path)
 {
     MString m;
     m += base;
     m += '/';
     m += path;
-    return FString(m);
+    return AString(m);
 }
 
 static
@@ -71,9 +71,8 @@ bool parse_option(XString name, ZString value)
         workdir = value;
     else
     {
-        FString name_ = name;
         FPRINTF(stderr, "WARNING: ingnoring invalid option '%s' : '%s'\n",
-                name_, value);
+                AString(name), value);
         return false;
     }
     return true;
@@ -90,7 +89,7 @@ bool read_config(ZString filename)
         exit(1);
     }
 
-    FString line;
+    AString line;
     while (in.getline(line))
     {
         if (is_comment(line))
@@ -179,8 +178,8 @@ int main(int argc, char *argv[])
     PRINTF("Starting:\n");
     PRINTF("* workdir: %s\n",  workdir);
     PRINTF("* login_server: %s\n", login_server);
-    PRINTF("* map_server: %s\n", map_server);
     PRINTF("* char_server: %s\n", char_server);
+    PRINTF("* map_server: %s\n", map_server);
     {
         //make sure all possible file descriptors are free for use by the servers
         //if there are file descriptors higher than the max open from before the limit dropped, that's not our problem
diff --git a/src/strings/all.hpp b/src/strings/all.hpp
index 7fd543f..46d5366 100644
--- a/src/strings/all.hpp
+++ b/src/strings/all.hpp
@@ -21,7 +21,8 @@
 
 # include "base.hpp"
 # include "mstring.hpp"
-# include "fstring.hpp"
+# include "rstring.hpp"
+# include "astring.hpp"
 # include "tstring.hpp"
 # include "sstring.hpp"
 # include "zstring.hpp"
diff --git a/src/strings/astring.cpp b/src/strings/astring.cpp
new file mode 100644
index 0000000..f7cfa2e
--- /dev/null
+++ b/src/strings/astring.cpp
@@ -0,0 +1,229 @@
+#include "astring.hpp"
+//    strings/astring.cpp - Functions for astring.hpp
+//
+//    Copyright © 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
+//
+//    This file is part of The Mana World (Athena server)
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU General Public License for more details.
+//
+//    You should have received a copy of the GNU General Public License
+//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "mstring.hpp"
+#include "tstring.hpp"
+#include "sstring.hpp"
+#include "zstring.hpp"
+#include "xstring.hpp"
+#include "vstring.hpp"
+
+namespace strings
+{
+    static_assert(sizeof(AString) == 256, "AString");
+
+    static
+    void acpy(char (&dst)[255], const char (&src)[255])
+    {
+        std::copy(src + 0, src + 255, dst);
+    }
+
+    // TODO dedup all this code once I drop gcc 4.6 support
+    AString::AString()
+    : data{}, special()
+    {
+        new(r_ptr()) RString();
+        special = 255;
+    }
+
+    AString::AString(const AString& a)
+    : data(), special(a.special)
+    {
+        acpy(data, a.data);
+        if (special == 255)
+            new(r_ptr()) RString(*a.r_ptr());
+    }
+    AString::AString(AString&& a)
+    : data(), special(a.special)
+    {
+        acpy(data, a.data);
+        if (special == 255)
+            new(r_ptr()) RString(std::move(*a.r_ptr()));
+    }
+    AString& AString::operator = (const AString& a)
+    {
+        if (this == &a)
+            return *this;
+        if (special == 255)
+            r_ptr()->~RString();
+        acpy(data, a.data);
+        special = a.special;
+        if (special == 255)
+            new(r_ptr()) RString(*a.r_ptr());
+        return *this;
+    }
+    AString& AString::operator = (AString&& a)
+    {
+        std::swap(data, a.data);
+        std::swap(special, a.special);
+        return *this;
+    }
+    AString::AString(RString r)
+    : data{}, special()
+    {
+        new(r_ptr()) RString(std::move(r));
+        special = 255;
+    }
+    AString::~AString()
+    {
+        if (special == 255)
+            r_ptr()->~RString();
+    }
+
+    AString::AString(const MString& s)
+    : data{}, special()
+    {
+        if (s.size() > 255 || s.size() == 0)
+        {
+            new(r_ptr()) RString(s);
+            special = 255;
+        }
+        else
+        {
+            *std::copy(s.begin(), s.end(), data) = '\0';
+            special = 255 - s.size();
+        }
+    }
+
+    AString::AString(XPair p)
+    : data{}, special()
+    {
+        new(r_ptr()) RString();
+        special = 255;
+        *this = XString(p);
+    }
+
+    AString::AString(const TString& t)
+    : data{}, special()
+    {
+        new(r_ptr()) RString();
+        special = 255;
+        *this = XString(t);
+    }
+    AString::AString(const SString& s)
+    : data{}, special()
+    {
+        new(r_ptr()) RString();
+        special = 255;
+        *this = XString(s);
+    }
+    AString::AString(ZString z)
+    : data{}, special()
+    {
+        new(r_ptr()) RString();
+        special = 255;
+        *this = XString(z);
+    }
+    AString::AString(XString x)
+    : data{}, special()
+    {
+        if (const RString *r = x.base())
+        {
+            if (&*r->begin() == &*x.begin() && &*r->end() == &*x.end())
+            {
+                new(r_ptr()) RString(*r);
+                special = 255;
+                return;
+            }
+        }
+        if (x.size() > 255 || x.size() == 0)
+        {
+            new(r_ptr()) RString(x);
+            special = 255;
+        }
+        else
+        {
+            *std::copy(x.begin(), x.end(), data) = '\0';
+            special = 255 - x.size();
+        }
+    }
+
+    AString::iterator AString::begin() const
+    {
+        if (special == 255)
+            return &*r_ptr()->begin();
+        else
+            return data + 0;
+    }
+    AString::iterator AString::end() const
+    {
+        if (special == 255)
+            return &*r_ptr()->end();
+        else
+            return data + (255 - special);
+    }
+    const RString *AString::base() const
+    {
+        if (special == 255)
+            return r_ptr();
+        else
+            return nullptr;
+    }
+    const char *AString::c_str() const
+    {
+        return &*begin();
+    }
+
+    const char *decay_for_printf(const AString& as)
+    {
+        return as.c_str();
+    }
+
+    int do_vprint(AString& out, const char *fmt, va_list ap)
+    {
+        // TODO try with a fixed-size buffer first, then write
+        // directory into the allocated output?
+        int len;
+        {
+            va_list ap2;
+            va_copy(ap2, ap);
+            len = vsnprintf(nullptr, 0, fmt, ap2);
+            va_end(ap2);
+        }
+        char buffer[len + 1];
+        vsnprintf(buffer, len + 1, fmt, ap);
+
+        out = AString(buffer, buffer + len);
+        return len;
+    }
+
+    AStringConverter::AStringConverter(AString& s)
+    : out(s), mid(nullptr)
+    {}
+
+    AStringConverter::~AStringConverter()
+    {
+        if (mid)
+        {
+            out = ZString(really_construct_from_a_pointer, mid, nullptr);
+            free(mid);
+        }
+    }
+
+    char **AStringConverter::operator &()
+    {
+        return &mid;
+    }
+
+    AStringConverter convert_for_scanf(AString& s)
+    {
+        return AStringConverter(s);
+    }
+} // namespace strings
diff --git a/src/strings/astring.hpp b/src/strings/astring.hpp
new file mode 100644
index 0000000..e682ef0
--- /dev/null
+++ b/src/strings/astring.hpp
@@ -0,0 +1,98 @@
+#ifndef TMWA_STRINGS_ASTRING_HPP
+#define TMWA_STRINGS_ASTRING_HPP
+//    strings/astring.hpp - An owned, reference-counted immutable string.
+//
+//    Copyright © 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
+//
+//    This file is part of The Mana World (Athena server)
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU General Public License for more details.
+//
+//    You should have received a copy of the GNU General Public License
+//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# include <cstdarg>
+# include <cstring>
+
+# include "base.hpp"
+# include "rstring.hpp"
+
+namespace strings
+{
+    /// An owning string that has reached its final contents.
+    /// The storage is NUL-terminated
+    class AString : public _crtp_string<AString, AString, ZPair>
+    {
+        RString *align[0];
+        char data[255];
+        unsigned char special;
+        RString *r_ptr() { return reinterpret_cast<RString *>(data); }
+        const RString *r_ptr() const { return reinterpret_cast<const RString *>(data); }
+    public:
+        AString();
+        AString(const AString&);
+        AString(AString&&);
+        AString& operator = (const AString&);
+        AString& operator = (AString&&);
+        AString(RString);
+        ~AString();
+
+        explicit AString(const MString& s);
+
+        template<size_t n>
+        AString(char (&s)[n]) = delete;
+
+        template<size_t n>
+        AString(const char (&s)[n]);
+
+        template<class It>
+        AString(It b, It e);
+
+        AString(XPair p);
+        //AString(const AString&)
+        AString(const TString&);
+        AString(const SString&);
+        AString(ZString);
+        AString(XString);
+        template<uint8_t n>
+        AString(const VString<n>& v);
+
+        iterator begin() const;
+        iterator end() const;
+        const RString *base() const;
+        const char *c_str() const;
+    };
+
+    // cxxstdio helpers
+    // I think the conversion will happen automatically. TODO test this.
+    // Nope, it doesn't, since there's a template
+    // Actually, it might now.
+    const char *decay_for_printf(const AString& fs);
+
+    __attribute__((format(printf, 2, 0)))
+    int do_vprint(AString& out, const char *fmt, va_list ap);
+
+    class AStringConverter
+    {
+        AString& out;
+        char *mid;
+    public:
+        AStringConverter(AString& s);
+        ~AStringConverter();
+        char **operator &();
+    };
+
+    AStringConverter convert_for_scanf(AString& s);
+} // namespace strings
+
+# include "astring.tcc"
+
+#endif // TMWA_STRINGS_ASTRING_HPP
diff --git a/src/strings/astring.py b/src/strings/astring.py
new file mode 100644
index 0000000..ec1dafe
--- /dev/null
+++ b/src/strings/astring.py
@@ -0,0 +1,24 @@
+class AString(object):
+    ''' print an AString
+    '''
+    __slots__ = ('_value')
+    name = 'strings::AString'
+    enabled = True
+
+    def __init__(self, value):
+        self._value = value
+
+    def to_string(self):
+        return None
+
+    def children(self):
+        b = self._value['data']
+        s = self._value['special']
+        if s == 255:
+            b = b.cast(gdb.lookup_type('strings::RString').pointer())
+            yield 'allocated', b.dereference()
+        else:
+            b = b.cast(b.type.target().pointer())
+            n = 255
+            d = n - s
+            yield 'contained', b.lazy_string(length=d)
diff --git a/src/strings/astring.tcc b/src/strings/astring.tcc
new file mode 100644
index 0000000..ed07bd9
--- /dev/null
+++ b/src/strings/astring.tcc
@@ -0,0 +1,76 @@
+//    strings/astring.tcc - Inline functions for astring.hpp
+//
+//    Copyright © 2013 Ben Longbons <b.r.longbons@gmail.com>
+//
+//    This file is part of The Mana World (Athena server)
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU General Public License for more details.
+//
+//    You should have received a copy of the GNU General Public License
+//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "mstring.hpp"
+
+namespace strings
+{
+    template<size_t n>
+    AString::AString(const char (&s)[n])
+    : data{}, special()
+    {
+        XPair x = s;
+        if (x.size() > 255 || x.size() == 0)
+        {
+            new(r_ptr()) RString(x);
+            special = 255;
+        }
+        else
+        {
+            *std::copy(x.begin(), x.end(), data) = '\0';
+            special = 255 - x.size();
+        }
+    }
+
+    template<class It>
+    AString::AString(It b, It e)
+    : data{}, special()
+    {
+        if (!std::is_base_of<std::forward_iterator_tag, typename std::iterator_traits<It>::iterator_category>::value)
+        {
+            // can't use std::distance
+            MString m;
+            for (; b != e; ++b)
+                m += *b;
+            *this = AString(m); // will recurse
+            return;
+        }
+        auto d = std::distance(b, e);
+        if (d > 255 || d == 0)
+        {
+            new(r_ptr()) RString(b, e);
+            special = 255;
+        }
+        else
+        {
+            *std::copy(b, e, data) = '\0';
+            special = 255 - d;
+        }
+    }
+
+    template<uint8_t n>
+    AString::AString(const VString<n>& v)
+    : data{}, special()
+    {
+        *std::copy(v.begin(), v.end(), data) = '\0';
+        special = 255 - v.size();
+        if (!v)
+            new(r_ptr()) RString();
+    }
+} // namespace strings
diff --git a/src/strings/base.hpp b/src/strings/base.hpp
index 7461872..c081f70 100644
--- a/src/strings/base.hpp
+++ b/src/strings/base.hpp
@@ -88,7 +88,7 @@ namespace strings
         const T& _ref() const;
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
     public:
         size_t size() const;
         reverse_iterator rbegin() const;
diff --git a/src/strings/base.tcc b/src/strings/base.tcc
index 491b4ca..a5a57d0 100644
--- a/src/strings/base.tcc
+++ b/src/strings/base.tcc
@@ -104,7 +104,7 @@ namespace strings
         return _ref().end();
     }
     template<class T, class O, class P>
-    const FString *_crtp_string<T, O, P>::base() const
+    const RString *_crtp_string<T, O, P>::base() const
     {
         return _ref().base();
     }
diff --git a/src/strings/base_test.cpp b/src/strings/base_test.cpp
index cb41fa9..3f9900e 100644
--- a/src/strings/base_test.cpp
+++ b/src/strings/base_test.cpp
@@ -4,7 +4,7 @@
 
 #include "vstring.hpp"
 #include "xstring.hpp"
-#include "fstring.hpp"
+#include "rstring.hpp"
 
 using namespace strings;
 
@@ -18,7 +18,7 @@ static_assert(!string_comparison_allowed<_test, VString<1>>::value, "tv");
 static_assert(!string_comparison_allowed<_test, _test2>::value, "t2");
 static_assert(string_comparison_allowed<VString<1>, XString>::value, "vx");
 static_assert(string_comparison_allowed<XString, XString>::value, "xx");
-static_assert(string_comparison_allowed<XString, FString>::value, "xf");
+static_assert(string_comparison_allowed<XString, RString>::value, "xf");
 
 TEST(strings, contains)
 {
diff --git a/src/strings/fwd.hpp b/src/strings/fwd.hpp
index a865fc4..f2b4037 100644
--- a/src/strings/fwd.hpp
+++ b/src/strings/fwd.hpp
@@ -28,7 +28,8 @@ namespace strings
 {
     // owning
     class MString;
-    class FString;
+    class RString;
+    class AString;
     class TString; // C legacy version of SString
     class SString; // is this one really worth it?
 
@@ -46,7 +47,8 @@ namespace strings
 } // namespace strings
 
 using strings::MString;
-using strings::FString;
+using strings::RString;
+using strings::AString;
 using strings::TString;
 using strings::SString;
 
diff --git a/src/strings/fstring.cpp b/src/strings/rstring.cpp
index 97ef4b0..eb9d88a 100644
--- a/src/strings/fstring.cpp
+++ b/src/strings/rstring.cpp
@@ -1,5 +1,5 @@
-#include "fstring.hpp"
-//    strings/fstring.cpp - Functions for fstring.hpp
+#include "rstring.hpp"
+//    strings/rstring.cpp - Functions for rstring.hpp
 //
 //    Copyright © 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 //
@@ -27,26 +27,28 @@
 
 namespace strings
 {
-    uint8_t FString::empty_string_rep[sizeof(Rep) + 1];
+    static_assert(sizeof(RString) == sizeof(const char *), "RString");
 
-    FString::FString()
+    uint8_t RString::empty_string_rep[sizeof(Rep) + 1];
+
+    RString::RString()
     : owned(reinterpret_cast<Rep *>(&empty_string_rep))
     {
         owned->count++;
     }
 
-    FString::FString(const FString& r)
+    RString::RString(const RString& r)
     : owned(r.owned)
     {
         owned->count++;
     }
-    FString::FString(FString&& r)
+    RString::RString(RString&& r)
     : owned(reinterpret_cast<Rep *>(&empty_string_rep))
     {
         std::swap(owned, r.owned);
         r.owned->count++;
     }
-    FString& FString::operator = (const FString& r)
+    RString& RString::operator = (const RString& r)
     {
         // order important for self-assign
         r.owned->count++;
@@ -57,49 +59,61 @@ namespace strings
         owned = r.owned;
         return *this;
     }
-    FString& FString::operator = (FString&& r)
+    RString& RString::operator = (RString&& r)
     {
         std::swap(owned, r.owned);
         return *this;
     }
-    FString::~FString()
+    RString::RString(AString a)
+    : owned(nullptr)
+    {
+        if (RString *r = const_cast<RString *>(a.base()))
+        {
+            *this = std::move(*r);
+        }
+        else
+        {
+            *this = XPair(a);
+        }
+    }
+    RString::~RString()
     {
         if (owned && !owned->count--)
             ::operator delete(owned);
         owned = nullptr;
     }
 
-    FString::FString(const MString& s)
+    RString::RString(const MString& s)
     : owned(nullptr)
     {
         _assign(s.begin(), s.end());
     }
 
-    FString::FString(XPair p)
+    RString::RString(XPair p)
     : owned(nullptr)
     {
         _assign(p.begin(), p.end());
     }
 
-    FString::FString(const TString& t)
+    RString::RString(const TString& t)
     : owned(nullptr)
     {
         *this = XString(t);
     }
-    FString::FString(const SString& s)
+    RString::RString(const SString& s)
     : owned(nullptr)
     {
         *this = XString(s);
     }
-    FString::FString(ZString z)
+    RString::RString(ZString z)
     : owned(nullptr)
     {
         *this = XString(z);
     }
-    FString::FString(XString x)
+    RString::RString(XString x)
     : owned(nullptr)
     {
-        const FString *f = x.base();
+        const RString *f = x.base();
         const char *xb = &*x.begin();
         const char *xe = &*x.end();
         const char *fb = f ? &*f->begin() : nullptr;
@@ -110,29 +124,29 @@ namespace strings
             _assign(x.begin(), x.end());
     }
 
-    FString::iterator FString::begin() const
+    RString::iterator RString::begin() const
     {
         return owned->body;
     }
-    FString::iterator FString::end() const
+    RString::iterator RString::end() const
     {
         return owned->body + owned->size;
     }
-    const FString *FString::base() const
+    const RString *RString::base() const
     {
         return this;
     }
-    const char *FString::c_str() const
+    const char *RString::c_str() const
     {
         return &*begin();
     }
 
-    const char *decay_for_printf(const FString& fs)
+    const char *decay_for_printf(const RString& fs)
     {
         return fs.c_str();
     }
 
-    int do_vprint(FString& out, const char *fmt, va_list ap)
+    int do_vprint(RString& out, const char *fmt, va_list ap)
     {
         int len;
         {
@@ -144,30 +158,7 @@ namespace strings
         char buffer[len + 1];
         vsnprintf(buffer, len + 1, fmt, ap);
 
-        out = FString(buffer, buffer + len);
+        out = RString(buffer, buffer + len);
         return len;
     }
-
-    StringConverter::StringConverter(FString& s)
-    : out(s), mid(nullptr)
-    {}
-
-    StringConverter::~StringConverter()
-    {
-        if (mid)
-        {
-            out = ZString(really_construct_from_a_pointer, mid, nullptr);
-            free(mid);
-        }
-    }
-
-    char **StringConverter::operator &()
-    {
-        return &mid;
-    }
-
-    StringConverter convert_for_scanf(FString& s)
-    {
-        return StringConverter(s);
-    }
 } // namespace strings
diff --git a/src/strings/fstring.hpp b/src/strings/rstring.hpp
index 48da326..b79c7f6 100644
--- a/src/strings/fstring.hpp
+++ b/src/strings/rstring.hpp
@@ -1,6 +1,6 @@
-#ifndef TMWA_STRINGS_FSTRING_HPP
-#define TMWA_STRINGS_FSTRING_HPP
-//    strings/fstring.hpp - An owned, reference-counted immutable string.
+#ifndef TMWA_STRINGS_RSTRING_HPP
+#define TMWA_STRINGS_RSTRING_HPP
+//    strings/rstring.hpp - An owned, reference-counted immutable string.
 //
 //    Copyright © 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 //
@@ -28,7 +28,7 @@ namespace strings
 {
     /// An owning string that has reached its final contents.
     /// The storage is NUL-terminated
-    class FString : public _crtp_string<FString, FString, ZPair>
+    class RString : public _crtp_string<RString, RString, ZPair>
     {
         struct Rep
         {
@@ -44,36 +44,37 @@ namespace strings
         template<class It>
         void _assign(It b, It e);
     public:
-        FString();
-        FString(const FString&);
-        FString(FString&&);
-        FString& operator = (const FString&);
-        FString& operator = (FString&&);
-        ~FString();
+        RString();
+        RString(const RString&);
+        RString(RString&&);
+        RString& operator = (const RString&);
+        RString& operator = (RString&&);
+        RString(AString);
+        ~RString();
 
-        explicit FString(const MString& s);
+        explicit RString(const MString& s);
 
         template<size_t n>
-        FString(char (&s)[n]) = delete;
+        RString(char (&s)[n]) = delete;
 
         template<size_t n>
-        FString(const char (&s)[n]);
+        RString(const char (&s)[n]);
 
         template<class It>
-        FString(It b, It e);
-
-        FString(XPair p);
-        //FString(const FString&)
-        FString(const TString&);
-        FString(const SString&);
-        FString(ZString);
-        FString(XString);
+        RString(It b, It e);
+
+        RString(XPair p);
+        //RString(const RString&)
+        RString(const TString&);
+        RString(const SString&);
+        RString(ZString);
+        RString(XString);
         template<uint8_t n>
-        FString(const VString<n>& v);
+        RString(const VString<n>& v);
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
         const char *c_str() const;
     };
 
@@ -81,24 +82,12 @@ namespace strings
     // I think the conversion will happen automatically. TODO test this.
     // Nope, it doesn't, since there's a template
     // Actually, it might now.
-    const char *decay_for_printf(const FString& fs);
+    const char *decay_for_printf(const RString& fs);
 
     __attribute__((format(printf, 2, 0)))
-    int do_vprint(FString& out, const char *fmt, va_list ap);
-
-    class StringConverter
-    {
-        FString& out;
-        char *mid;
-    public:
-        StringConverter(FString& s);
-        ~StringConverter();
-        char **operator &();
-    };
-
-    StringConverter convert_for_scanf(FString& s);
+    int do_vprint(RString& out, const char *fmt, va_list ap);
 } // namespace strings
 
-# include "fstring.tcc"
+# include "rstring.tcc"
 
-#endif // TMWA_STRINGS_FSTRING_HPP
+#endif // TMWA_STRINGS_RSTRING_HPP
diff --git a/src/strings/fstring.py b/src/strings/rstring.py
index 5418300..f0618d6 100644
--- a/src/strings/fstring.py
+++ b/src/strings/rstring.py
@@ -1,8 +1,8 @@
-class FString(object):
-    ''' print a FString
+class RString(object):
+    ''' print a RString
     '''
     __slots__ = ('_value')
-    name = 'strings::FString'
+    name = 'strings::RString'
     enabled = True
 
     def __init__(self, value):
diff --git a/src/strings/fstring.tcc b/src/strings/rstring.tcc
index 8072fb0..8b4c0c0 100644
--- a/src/strings/fstring.tcc
+++ b/src/strings/rstring.tcc
@@ -1,4 +1,4 @@
-//    strings/fstring.tcc - Inline functions for fstring.hpp
+//    strings/rstring.tcc - Inline functions for rstring.hpp
 //
 //    Copyright © 2013 Ben Longbons <b.r.longbons@gmail.com>
 //
@@ -22,12 +22,12 @@
 namespace strings
 {
     template<class It>
-    void FString::_assign(It b, It e)
+    void RString::_assign(It b, It e)
     {
         owned = nullptr;
         if (b == e)
         {
-            *this = FString();
+            *this = RString();
             return;
         }
         if (!std::is_base_of<std::forward_iterator_tag, typename std::iterator_traits<It>::iterator_category>::value)
@@ -36,7 +36,7 @@ namespace strings
             MString m;
             for (; b != e; ++b)
                 m += *b;
-            *this = FString(m); // will recurse
+            *this = RString(m); // will recurse
             return;
         }
         size_t diff = std::distance(b, e);
@@ -48,19 +48,19 @@ namespace strings
     }
 
     template<size_t n>
-    FString::FString(const char (&s)[n])
+    RString::RString(const char (&s)[n])
     {
         _assign(s, s + strlen(s));
     }
 
     template<class It>
-    FString::FString(It b, It e)
+    RString::RString(It b, It e)
     {
         _assign(b, e);
     }
 
     template<uint8_t n>
-    FString::FString(const VString<n>& v)
+    RString::RString(const VString<n>& v)
     {
         _assign(v.begin(), v.end());
     }
diff --git a/src/strings/sstring.cpp b/src/strings/sstring.cpp
index 99f91ed..fee98f9 100644
--- a/src/strings/sstring.cpp
+++ b/src/strings/sstring.cpp
@@ -27,8 +27,11 @@ namespace strings
     SString::SString()
     : _s(), _b(), _e()
     {}
-    SString::SString(FString f)
-    : _s(std::move(f)), _b(), _e(_s.size())
+    SString::SString(RString r)
+    : _s(std::move(r)), _b(), _e(_s.size())
+    {}
+    SString::SString(AString a)
+    : _s(std::move(a)), _b(), _e(_s.size())
     {}
     SString::SString(TString t)
     : _s(t._s), _b(0), _e(_s.size())
@@ -39,19 +42,39 @@ namespace strings
     }
     SString::SString(const XString& x)
     {
-        const FString *f = x.base();
+        const RString *r = x.base();
         const char *xb = &*x.begin();
         const char *xe = &*x.end();
-        const char *fb = f ? &*f->begin() : nullptr;
-        //const char *fe = f ? &*f->end() : nullptr;
-        if (f)
-            *this = SString(*f, xb - fb, xe - fb);
+        const char *rb = r ? &*r->begin() : nullptr;
+        //const char *re = r ? &*r->end() : nullptr;
+        if (r)
+            *this = SString(*r, xb - rb, xe - rb);
         else
-            *this = FString(x);
+            *this = RString(x);
     }
 
-    SString::SString(FString f, size_t b, size_t e)
-    : _s(std::move(f)), _b(b), _e(e)
+    SString::SString(RString r, size_t b, size_t e)
+    : _s(std::move(r)), _b(b), _e(e)
+    {}
+    static
+    RString get_owned_slice(AString a, size_t *b, size_t *e)
+    {
+        if (a.base())
+        {
+            // it's futile
+            return std::move(a);
+        }
+        // have to allocate anyway, so cut first
+        size_t ob = *b;
+        size_t oe = *e;
+        *e -= *b;
+        *b = 0;
+        return a.xpslice(ob, oe);
+    }
+    SString::SString(AString a, size_t b, size_t e)
+    : _s(get_owned_slice(std::move(a), &b, &e))
+    , _b(b)
+    , _e(e)
     {}
     SString::SString(XPair p)
     : _s(p), _b(0), _e(p.size())
@@ -65,7 +88,7 @@ namespace strings
     {
         return &_s.begin()[_e];
     }
-    const FString *SString::base() const
+    const RString *SString::base() const
     {
         return &_s;
     }
diff --git a/src/strings/sstring.hpp b/src/strings/sstring.hpp
index 12fb96d..1836d69 100644
--- a/src/strings/sstring.hpp
+++ b/src/strings/sstring.hpp
@@ -1,6 +1,6 @@
 #ifndef TMWA_STRINGS_SSTRING_HPP
 #define TMWA_STRINGS_SSTRING_HPP
-//    strings/sstring.hpp - A full slice of an FString.
+//    strings/sstring.hpp - A full slice of an RString.
 //
 //    Copyright © 2013 Ben Longbons <b.r.longbons@gmail.com>
 //
@@ -20,19 +20,20 @@
 //    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # include "base.hpp"
-# include "fstring.hpp"
+# include "rstring.hpp"
 
 namespace strings
 {
-    /// An owning string that represents a arbitrary slice of an FString.
+    /// An owning string that represents a arbitrary slice of an RString.
     /// Not guaranteed to be NUL-terminated.
     class SString : public _crtp_string<SString, SString, XPair>
     {
-        FString _s;
+        RString _s;
         size_t _b, _e;
     public:
         SString();
-        SString(FString f);
+        SString(RString f);
+        SString(AString f);
         SString(TString t);
         //SString(const SString&);
         SString(const ZString&);
@@ -45,12 +46,13 @@ namespace strings
         SString(const char (&s)[n]);
         //template<class It>
         //SString(It b, It e) : _s(b, e), _b(0), _e(_s.size()) {}
-        SString(FString f, size_t b, size_t e);
+        SString(RString f, size_t b, size_t e);
+        SString(AString f, size_t b, size_t e);
         SString(XPair p);
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
     };
 } // namespace strings
 
diff --git a/src/strings/strings2_test.cpp b/src/strings/strings2_test.cpp
index 3f8662a..24bfc0c 100644
--- a/src/strings/strings2_test.cpp
+++ b/src/strings/strings2_test.cpp
@@ -6,7 +6,7 @@ TEST(StringTests, traits2)
 {
     ZString print_non = "\t\e";
     ZString print_mix = "n\t";
-    FString print_all = "n ";
+    RString print_all = "n ";
     EXPECT_FALSE(print_non.has_print());
     EXPECT_TRUE(print_mix.has_print());
     EXPECT_TRUE(print_all.has_print());
@@ -20,7 +20,7 @@ TEST(StringTests, traits2)
 
     ZString graph_non = " \e";
     ZString graph_mix = "n ";
-    FString graph_all = "n.";
+    RString graph_all = "n.";
     EXPECT_FALSE(graph_non.has_graph());
     EXPECT_TRUE(graph_mix.has_graph());
     EXPECT_TRUE(graph_all.has_graph());
@@ -30,7 +30,7 @@ TEST(StringTests, traits2)
 
     ZString lower_non = "0A";
     ZString lower_mix = "Oa";
-    FString lower_all = "oa";
+    RString lower_all = "oa";
     EXPECT_FALSE(lower_non.has_lower());
     EXPECT_TRUE(lower_mix.has_lower());
     EXPECT_TRUE(lower_all.has_lower());
@@ -44,7 +44,7 @@ TEST(StringTests, traits2)
 
     ZString upper_non = "0a";
     ZString upper_mix = "oA";
-    FString upper_all = "OA";
+    RString upper_all = "OA";
     EXPECT_FALSE(upper_non.has_upper());
     EXPECT_TRUE(upper_mix.has_upper());
     EXPECT_TRUE(upper_all.has_upper());
@@ -58,7 +58,7 @@ TEST(StringTests, traits2)
 
     ZString alpha_non = " 0";
     ZString alpha_mix = "n ";
-    FString alpha_all = "nA";
+    RString alpha_all = "nA";
     EXPECT_FALSE(alpha_non.has_alpha());
     EXPECT_TRUE(alpha_mix.has_alpha());
     EXPECT_TRUE(alpha_all.has_alpha());
@@ -68,7 +68,7 @@ TEST(StringTests, traits2)
 
     ZString digit2_non = "a9";
     ZString digit2_mix = "20";
-    FString digit2_all = "01";
+    RString digit2_all = "01";
     EXPECT_FALSE(digit2_non.has_digit2());
     EXPECT_TRUE(digit2_mix.has_digit2());
     EXPECT_TRUE(digit2_all.has_digit2());
@@ -78,7 +78,7 @@ TEST(StringTests, traits2)
 
     ZString digit8_non = "a9";
     ZString digit8_mix = "80";
-    FString digit8_all = "37";
+    RString digit8_all = "37";
     EXPECT_FALSE(digit8_non.has_digit8());
     EXPECT_TRUE(digit8_mix.has_digit8());
     EXPECT_TRUE(digit8_all.has_digit8());
@@ -88,7 +88,7 @@ TEST(StringTests, traits2)
 
     ZString digit10_non = "az";
     ZString digit10_mix = "a9";
-    FString digit10_all = "42";
+    RString digit10_all = "42";
     EXPECT_FALSE(digit10_non.has_digit10());
     EXPECT_TRUE(digit10_mix.has_digit10());
     EXPECT_TRUE(digit10_all.has_digit10());
@@ -98,7 +98,7 @@ TEST(StringTests, traits2)
 
     ZString digit16_non = "gz";
     ZString digit16_mix = "ao";
-    FString digit16_all = "be";
+    RString digit16_all = "be";
     EXPECT_FALSE(digit16_non.has_digit16());
     EXPECT_TRUE(digit16_mix.has_digit16());
     EXPECT_TRUE(digit16_all.has_digit16());
@@ -108,7 +108,7 @@ TEST(StringTests, traits2)
 
     ZString alnum_non = " .";
     ZString alnum_mix = "n ";
-    FString alnum_all = "n0";
+    RString alnum_all = "n0";
     EXPECT_FALSE(alnum_non.has_alnum());
     EXPECT_TRUE(alnum_mix.has_alnum());
     EXPECT_TRUE(alnum_all.has_alnum());
@@ -116,3 +116,89 @@ TEST(StringTests, traits2)
     EXPECT_FALSE(alnum_mix.is_alnum());
     EXPECT_TRUE(alnum_all.is_alnum());
 }
+
+TEST(StringTests, rempty)
+{
+    const char empty_text[] = "";
+    RString r = empty_text;
+    EXPECT_EQ(r.size(), 0);
+    AString a = empty_text;
+    EXPECT_EQ(r, a);
+    AString r2 = r, r3;
+    RString a2 = a, a3;
+    XString r1 = r2;
+    XString a1 = a2;
+    r3 = r1;
+    a3 = a1;
+    EXPECT_EQ(r, r1);
+    EXPECT_EQ(a, a1);
+    EXPECT_EQ(r, r2);
+    EXPECT_EQ(a, a2);
+    EXPECT_EQ(r, r3);
+    EXPECT_EQ(a, a3);
+    EXPECT_EQ(&*r.begin(), &*r1.begin());
+    EXPECT_EQ(&*a.begin(), &*a1.begin());
+    EXPECT_EQ(&*r.begin(), &*r2.begin());
+    EXPECT_EQ(&*a.begin(), &*a2.begin());
+    EXPECT_EQ(&*r.begin(), &*r3.begin());
+    EXPECT_EQ(&*a.begin(), &*a3.begin());
+}
+TEST(StringTests, rshort)
+{
+    const char short_text[] = "0123456789";
+    RString r = short_text;
+    EXPECT_EQ(r.size(), 10);
+    AString a = short_text;
+    EXPECT_EQ(r, a);
+    AString r2 = r, r3;
+    RString a2 = a, a3;
+    XString r1 = r2;
+    XString a1 = a2;
+    r3 = r1;
+    a3 = a1;
+    EXPECT_EQ(r, r1);
+    EXPECT_EQ(a, a1);
+    EXPECT_EQ(r, r2);
+    EXPECT_EQ(a, a2);
+    EXPECT_EQ(r, r3);
+    EXPECT_EQ(a, a3);
+    EXPECT_EQ(&*r.begin(), &*r1.begin());
+    EXPECT_NE(&*a.begin(), &*a1.begin());
+    EXPECT_EQ(&*r.begin(), &*r2.begin());
+    EXPECT_NE(&*a.begin(), &*a2.begin());
+    EXPECT_EQ(&*r.begin(), &*r3.begin());
+    EXPECT_NE(&*a.begin(), &*a3.begin());
+}
+
+TEST(StringTests, rlong)
+{
+    const char long_text[] =
+        "01234567890123456789012345678901234567890123456789"
+        "0123456789012345678901234567890123456789012345 100"
+        "01234567890123456789012345678901234567890123456789"
+        "0123456789012345678901234567890123456789012345 200"
+        "01234567890123456789012345678901234567890123456789"
+        "0123456789012345678901234567890123456789012345 300";
+    RString r = long_text;
+    EXPECT_EQ(r.size(), 300);
+    AString a = long_text;
+    EXPECT_EQ(r, a);
+    AString r2 = r, r3;
+    RString a2 = a, a3;
+    XString r1 = r2;
+    XString a1 = a2;
+    r3 = r1;
+    a3 = a1;
+    EXPECT_EQ(r, r1);
+    EXPECT_EQ(a, a1);
+    EXPECT_EQ(r, r2);
+    EXPECT_EQ(a, a2);
+    EXPECT_EQ(r, r3);
+    EXPECT_EQ(a, a3);
+    EXPECT_EQ(&*r.begin(), &*r1.begin());
+    EXPECT_EQ(&*a.begin(), &*a1.begin());
+    EXPECT_EQ(&*r.begin(), &*r2.begin());
+    EXPECT_EQ(&*a.begin(), &*a2.begin());
+    EXPECT_EQ(&*r.begin(), &*r3.begin());
+    EXPECT_EQ(&*a.begin(), &*a3.begin());
+}
diff --git a/src/strings/strings_test.cpp b/src/strings/strings_test.cpp
index 82d39d8..55a2ffa 100644
--- a/src/strings/strings_test.cpp
+++ b/src/strings/strings_test.cpp
@@ -21,7 +21,7 @@ TYPED_TEST_P(StringTest, basic)
     EXPECT_EQ(0, hi0.size());
 
     __attribute__((unused))
-    const FString *base = hi.base();
+    const RString *base = hi.base();
 }
 
 TYPED_TEST_P(StringTest, order)
@@ -168,7 +168,8 @@ TYPED_TEST_P(StringTest, convert)
     constexpr bool is_zstring = std::is_same<TypeParam, ZString>::value;
     typedef typename std::conditional<is_zstring, TString, SString>::type Sstring;
     typedef typename std::conditional<is_zstring, ZString, XString>::type Xstring;
-    FString f = "f";
+    RString r = "r";
+    AString a = "a";
     TString t = "t";
     Sstring s = "s";
     ZString z = "z";
@@ -177,7 +178,8 @@ TYPED_TEST_P(StringTest, convert)
     const char l[] = "l";
     VString<5> hi = "hello";
 
-    TypeParam f2 = f;
+    TypeParam r2 = r;
+    TypeParam a2 = a;
     TypeParam t2 = t;
     TypeParam s2 = s;
     TypeParam z2 = z;
@@ -186,7 +188,8 @@ TYPED_TEST_P(StringTest, convert)
     TypeParam l2 = l;
     TypeParam hi2 = hi;
 
-    EXPECT_EQ(f, f2);
+    EXPECT_EQ(r, r2);
+    EXPECT_EQ(a, a2);
     EXPECT_EQ(t, t2);
     EXPECT_EQ(s, s2);
     EXPECT_EQ(z, z2);
@@ -195,8 +198,9 @@ TYPED_TEST_P(StringTest, convert)
     EXPECT_EQ(l, l2);
     EXPECT_EQ(hi, hi2);
 
-    TypeParam f3, t3, s3, z3, x3, v3, l3, hi3;
-    f3 = f;
+    TypeParam r3, a3, t3, s3, z3, x3, v3, l3, hi3;
+    r3 = r;
+    a3 = a;
     t3 = t;
     s3 = s;
     z3 = z;
@@ -205,7 +209,8 @@ TYPED_TEST_P(StringTest, convert)
     l3 = l;
     hi3 = hi;
 
-    EXPECT_EQ(f, f3);
+    EXPECT_EQ(r, r3);
+    EXPECT_EQ(a, a3);
     EXPECT_EQ(t, t3);
     EXPECT_EQ(s, s3);
     EXPECT_EQ(z, z3);
@@ -214,7 +219,8 @@ TYPED_TEST_P(StringTest, convert)
     EXPECT_EQ(l, l3);
     EXPECT_EQ(hi, hi3);
 
-    TypeParam f4(f);
+    TypeParam r4(r);
+    TypeParam a4(a);
     TypeParam t4(t);
     TypeParam s4(s);
     TypeParam z4(z);
@@ -223,7 +229,8 @@ TYPED_TEST_P(StringTest, convert)
     TypeParam l4(l);
     TypeParam hi4(hi);
 
-    EXPECT_EQ(f, f4);
+    EXPECT_EQ(r, r4);
+    EXPECT_EQ(a, a4);
     EXPECT_EQ(t, t4);
     EXPECT_EQ(s, s4);
     EXPECT_EQ(z, z4);
@@ -237,7 +244,7 @@ REGISTER_TYPED_TEST_CASE_P(StringTest,
         basic, order, iterators, xslice, convert);
 
 typedef ::testing::Types<
-    FString, TString, SString, ZString, XString, VString<255>
+    RString, AString, TString, SString, ZString, XString, VString<255>
 > MostStringTypes;
 INSTANTIATE_TYPED_TEST_CASE_P(StringStuff, StringTest, MostStringTypes);
 
@@ -274,6 +281,6 @@ REGISTER_TYPED_TEST_CASE_P(NulStringTest,
         basic);
 
 typedef ::testing::Types<
-    FString, TString, ZString, VString<255>
+    RString, AString, TString, ZString, VString<255>
 > NulStringTypes;
 INSTANTIATE_TYPED_TEST_CASE_P(NulStringStuff, NulStringTest, NulStringTypes);
diff --git a/src/strings/tstring.cpp b/src/strings/tstring.cpp
index 2d13888..8be7112 100644
--- a/src/strings/tstring.cpp
+++ b/src/strings/tstring.cpp
@@ -27,9 +27,24 @@ namespace strings
     TString::TString()
     : _s(), _o()
     {}
-    TString::TString(FString b, size_t i)
+    TString::TString(RString b, size_t i)
     : _s(std::move(b)), _o(i)
     {}
+    static
+    RString get_owned_tlice(AString a, size_t *i)
+    {
+        if (a.base())
+        {
+            return std::move(a);
+        }
+        size_t oi = *i;
+        *i = 0;
+        return a.xslice_t(oi);
+    }
+    TString::TString(AString b, size_t i)
+    : _s(get_owned_tlice(std::move(b), &i))
+    , _o(i)
+    {}
     TString::TString(const SString& s)
     {
         *this = XString(s);
@@ -40,15 +55,15 @@ namespace strings
     }
     TString::TString(const XString& x)
     {
-        const FString *f = x.base();
+        const RString *r = x.base();
         const char *xb = &*x.begin();
         const char *xe = &*x.end();
-        const char *fb = f ? &*f->begin() : nullptr;
-        const char *fe = f ? &*f->end() : nullptr;
-        if (f && xe == fe)
-            *this = TString(*f, xb - fb);
+        const char *rb = r ? &*r->begin() : nullptr;
+        const char *re = r ? &*r->end() : nullptr;
+        if (r && xe == re)
+            *this = TString(*r, xb - rb);
         else
-            *this = FString(x);
+            *this = RString(x);
     }
 
     TString::TString(XPair p)
@@ -63,7 +78,7 @@ namespace strings
     {
         return &*_s.end();
     }
-    const FString *TString::base() const
+    const RString *TString::base() const
     {
         return &_s;
     }
diff --git a/src/strings/tstring.hpp b/src/strings/tstring.hpp
index 49ec4ab..700ec3d 100644
--- a/src/strings/tstring.hpp
+++ b/src/strings/tstring.hpp
@@ -20,20 +20,21 @@
 //    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # include "base.hpp"
-# include "fstring.hpp"
+# include "rstring.hpp"
 
 namespace strings
 {
-    /// An owning string that represents a tail slice of an FString.
+    /// An owning string that represents a tail slice of an RString.
     /// Guaranteed to be NUL-terminated.
     class TString : public _crtp_string<TString, TString, ZPair>
     {
         friend class SString;
-        FString _s;
+        RString _s;
         size_t _o;
     public:
         TString();
-        TString(FString b, size_t i=0);
+        TString(RString b, size_t i=0);
+        TString(AString b, size_t i=0);
         //TString(const TString&)
         TString(const SString&);
         TString(const ZString&);
@@ -50,7 +51,7 @@ namespace strings
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
         const char *c_str() const;
     };
 
diff --git a/src/strings/vstring.hpp b/src/strings/vstring.hpp
index c07c32a..183e782 100644
--- a/src/strings/vstring.hpp
+++ b/src/strings/vstring.hpp
@@ -31,7 +31,8 @@ namespace strings
     public:
         typedef typename _crtp_string<VString<n>, VString<n>, ZPair>::iterator iterator;
         VString(XString x);
-        VString(FString f);
+        VString(RString f);
+        VString(AString f);
         VString(TString t);
         VString(SString s);
         VString(ZString z);
@@ -48,7 +49,7 @@ namespace strings
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
         const char *c_str() const;
     };
 
diff --git a/src/strings/vstring.tcc b/src/strings/vstring.tcc
index 674b21d..69729d4 100644
--- a/src/strings/vstring.tcc
+++ b/src/strings/vstring.tcc
@@ -21,7 +21,8 @@
 
 #include "../common/utils2.hpp"
 
-#include "fstring.hpp"
+#include "rstring.hpp"
+#include "astring.hpp"
 #include "tstring.hpp"
 #include "sstring.hpp"
 #include "zstring.hpp"
@@ -43,11 +44,16 @@ namespace strings
     // poor man's delegated constructors
     // needed for gcc 4.6 compatibility
     template<uint8_t n>
-    VString<n>::VString(FString f)
+    VString<n>::VString(RString f)
     {
         *this = XString(f);
     }
     template<uint8_t n>
+    VString<n>::VString(AString a)
+    {
+        *this = XString(a);
+    }
+    template<uint8_t n>
     VString<n>::VString(TString t)
     {
         *this = XString(t);
@@ -109,7 +115,7 @@ namespace strings
         return std::end(_data) - _special;
     }
     template<uint8_t n>
-    const FString *VString<n>::base() const
+    const RString *VString<n>::base() const
     {
         return nullptr;
     }
diff --git a/src/strings/xstring.cpp b/src/strings/xstring.cpp
index 107217b..8a604c7 100644
--- a/src/strings/xstring.cpp
+++ b/src/strings/xstring.cpp
@@ -23,7 +23,10 @@ namespace strings
     XString::XString()
     : _b(""), _e(_b), _base()
     {}
-    XString::XString(const FString& s)
+    XString::XString(const RString& s)
+    : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
+    {}
+    XString::XString(const AString& s)
     : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
     {}
     XString::XString(const TString& s)
@@ -36,10 +39,10 @@ namespace strings
     : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
     {}
 
-    XString::XString(const char *b, const char *e, const FString *base_)
+    XString::XString(const char *b, const char *e, const RString *base_)
     : _b(b), _e(e), _base(base_)
     {}
-    XString::XString(decltype(really_construct_from_a_pointer) e, const char *s, const FString *base_)
+    XString::XString(decltype(really_construct_from_a_pointer) e, const char *s, const RString *base_)
     {
         *this = ZString(e, s, base_);
     }
@@ -55,7 +58,7 @@ namespace strings
     {
         return _e;
     }
-    const FString *XString::base() const
+    const RString *XString::base() const
     {
         return _base;
     }
diff --git a/src/strings/xstring.hpp b/src/strings/xstring.hpp
index e96ef8a..2766810 100644
--- a/src/strings/xstring.hpp
+++ b/src/strings/xstring.hpp
@@ -25,17 +25,18 @@ namespace strings
 {
     /// A non-owning string that is not guaranteed to be NUL-terminated.
     /// This should be only used as a parameter.
-    class XString : public _crtp_string<XString, FString, XPair>
+    class XString : public _crtp_string<XString, AString, XPair>
     {
         iterator _b, _e;
         // optional
-        const FString *_base;
+        const RString *_base;
     public:
         // do I really want this?
         XString();
         XString(std::nullptr_t) = delete;
         // no MString
-        XString(const FString& s);
+        XString(const RString& s);
+        XString(const AString& s);
         XString(const TString& s);
         XString(const SString& s);
         XString(const ZString& s);
@@ -46,13 +47,13 @@ namespace strings
         template<size_t n>
         XString(const char (&s)[n]);
         // mostly internal
-        XString(const char *b, const char *e, const FString *base_);
-        XString(decltype(really_construct_from_a_pointer) e, const char *s, const FString *base_);
+        XString(const char *b, const char *e, const RString *base_);
+        XString(decltype(really_construct_from_a_pointer) e, const char *s, const RString *base_);
         XString(XPair p);
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
     };
 } // namespace strings
 
diff --git a/src/strings/zstring.cpp b/src/strings/zstring.cpp
index 0de836c..bfc0c96 100644
--- a/src/strings/zstring.cpp
+++ b/src/strings/zstring.cpp
@@ -26,16 +26,19 @@ namespace strings
     {
         *this = ZString("");
     }
-    ZString::ZString(const FString& s)
+    ZString::ZString(const RString& s)
+    : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
+    {}
+    ZString::ZString(const AString& s)
     : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
     {}
     ZString::ZString(const TString& s)
     : _b(&*s.begin()), _e(&*s.end()), _base(s.base())
     {}
-    ZString::ZString(const char *b, const char *e, const FString *base_)
+    ZString::ZString(const char *b, const char *e, const RString *base_)
     : _b(b), _e(e), _base(base_)
     {}
-    ZString::ZString(decltype(really_construct_from_a_pointer), const char *s, const FString *base_)
+    ZString::ZString(decltype(really_construct_from_a_pointer), const char *s, const RString *base_)
     : _b(s), _e(s + strlen(s)), _base(base_)
     {}
 
@@ -47,7 +50,7 @@ namespace strings
     {
         return _e;
     }
-    const FString *ZString::base() const
+    const RString *ZString::base() const
     {
         return _base;
     }
diff --git a/src/strings/zstring.hpp b/src/strings/zstring.hpp
index 72a227c..96aadc0 100644
--- a/src/strings/zstring.hpp
+++ b/src/strings/zstring.hpp
@@ -27,15 +27,16 @@ namespace strings
 {
     /// A non-owning string that is guaranteed to be NUL-terminated.
     /// This should be only used as a parameter.
-    class ZString : public _crtp_string<ZString, FString, ZPair>
+    class ZString : public _crtp_string<ZString, AString, ZPair>
     {
         iterator _b, _e;
         // optional
-        const FString *_base;
+        const RString *_base;
     public:
         ZString();
         // no MString
-        ZString(const FString& s);
+        ZString(const RString& s);
+        ZString(const AString& s);
         ZString(const TString& s);
         ZString(const SString&) = delete;
         //ZString(ZString);
@@ -43,16 +44,16 @@ namespace strings
         template<uint8_t n>
         ZString(const VString<n>& s);
         // dangerous
-        ZString(const char *b, const char *e, const FString *base_);
-        ZString(decltype(really_construct_from_a_pointer), const char *s, const FString *base_);
+        ZString(const char *b, const char *e, const RString *base_);
+        ZString(decltype(really_construct_from_a_pointer), const char *s, const RString *base_);
         template<size_t n>
         ZString(char (&s)[n]) = delete;
         template<size_t n>
-        ZString(const char (&s)[n], const FString *base_=nullptr);
+        ZString(const char (&s)[n], const RString *base_=nullptr);
 
         iterator begin() const;
         iterator end() const;
-        const FString *base() const;
+        const RString *base() const;
         const char *c_str() const;
     };
 
diff --git a/src/strings/zstring.tcc b/src/strings/zstring.tcc
index 1065b7c..fe0e9f3 100644
--- a/src/strings/zstring.tcc
+++ b/src/strings/zstring.tcc
@@ -29,7 +29,7 @@ namespace strings
     {}
 
     template<size_t n>
-    ZString::ZString(const char (&s)[n], const FString *base_)
+    ZString::ZString(const char (&s)[n], const RString *base_)
     : _b(s), _e(s + strlen(s)), _base(base_)
     {}
 } // namespace strings