1 files changed, 78 insertions, 0 deletions
diff --git a/src/compat/result.hpp b/src/compat/result.hpp
new file mode 100644
index 0000000..f03c026
--- /dev/null
+++ b/src/compat/result.hpp
@@ -0,0 +1,78 @@
+#pragma once
+//    result.hpp - A possibly failed return value
+//
+//    Copyright © 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 "fwd.hpp"
+
+#include "../strings/rstring.hpp"
+
+#include "option.hpp"
+
+namespace tmwa
+{
+    namespace result
+    {
+        enum ResultMagicFlag { magic_flag };
+
+        template<class T>
+        class Result
+        {
+            Option<T> success;
+            RString failure;
+        public:
+            Result(ResultMagicFlag, T v)
+            : success(Some(std::move(v))), failure()
+            {}
+            Result(ResultMagicFlag, RString msg)
+            : success(None), failure(std::move(msg))
+            {}
+
+            bool is_ok() { return success.is_some(); }
+            bool is_err() { return !is_ok(); }
+
+            Option<T>& get_success() { return success; }
+            RString& get_failure() { return failure; }
+        };
+
+        template<class T>
+        Result<T> Ok(T v)
+        {
+            return Result<T>(magic_flag, std::move(v));
+        }
+
+        struct Err
+        {
+            RString message;
+            Err(RString m) : message(std::move(m)) {}
+
+            template<class T>
+            operator Result<T>()
+            {
+                return Result<T>(magic_flag, message);
+            }
+        };
+    } // namespace result
+    using result::Result;
+    using result::Ok;
+    using result::Err;
+
+#define TRY(r) ({ auto _res = r; TRY_UNWRAP(_res.get_success(), return ::tmwa::Err(_res.get_failure())); })
+    // TODO the existence of this as a separate macro is a bug.
+#define TRY_MOVE(r) ({ auto _res = r; TRY_UNWRAP(std::move(_res.get_success()), return ::tmwa::Err(_res.get_failure())); })
+} // namespace tmwa