Magically allow "break" within WITH_VAR

1 files changed, 24 insertions, 4 deletions

diff --git a/src/compat/attr.hpp b/src/compat/attr.hpp
index 5322a14..9ddf654 100644
--- a/src/compat/attr.hpp
+++ b/src/compat/attr.hpp
@@ -1,7 +1,7 @@
 #pragma once
 //    attr.hpp - Attributes.
 //
-//    Copyright © 2013 Ben Longbons <b.r.longbons@gmail.com>
+//    Copyright © 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 //
 //    This file is part of The Mana World (Athena server)
 //
@@ -31,7 +31,27 @@ namespace tmwa
 
 #define JOIN(a, b) a##b
 
-#define WITH_VAR(ty, var, expr)                                 \
-    for (bool JOIN(var, _guard) = true; JOIN(var, _guard); )    \
-        for (ty var = expr; JOIN(var, _guard); JOIN(var, _guard) = false)
+//  first loop:
+//      declare flag 'guard' (initially true)
+//      declare flag 'broken' (initially false)
+//      condition is 'guard' must be true, which is the case only for the first iteration
+//      post checks 'broken' and if set, break the loop
+//  second loop:
+//      declare public 'var' variable
+//      condition is that 'guard' must be true
+//      post sets 'guard' to false to make this loop run only once
+//  third loop:
+//      enable broken flag; it will remain set if 'break' is in the loop
+//      condition is that 'broken' must be true
+//      post sets 'broken' to false, which then fails the condition
+//      if user has a 'break' inside, then 'broken' will be true
+//      in either case, go back to the second loop's post
+#define WITH_VAR_INLOOP(ty, var, expr)                                                                                          \
+    for (bool JOIN(var, _guard) = true, JOIN(var, _broken) = false; JOIN(var, _guard); ({if (JOIN(var, _broken)) { break; } })) \
+        for (ty var = expr; JOIN(var, _guard); JOIN(var, _guard) = false)                                                       \
+            for (JOIN(var, _broken) = true; JOIN(var, _broken); JOIN(var, _broken) = false)
+#define WITH_VAR_NOLOOP(ty, var, expr)                                                                                          \
+    for (bool JOIN(var, _guard) = true, JOIN(var, _broken) = false; JOIN(var, _guard); ({if (JOIN(var, _broken)) {abort();} })) \
+        for (ty var = expr; JOIN(var, _guard); JOIN(var, _guard) = false)                                                       \
+            for (JOIN(var, _broken) = true; JOIN(var, _broken); JOIN(var, _broken) = false)
 } // namespace tmwa