Fix _CHOOSE to use the copies instead of double execution of side-e…

…ffects (issue reported by tromp at bitcointalk.org)
shelby3 · Dec 1, 2015 · b817c6c · b817c6c
1 parent bd4ea5b
commit b817c6c
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/cmacros/effectless.h b/cmacros/effectless.h
@@ -10,11 +10,11 @@ Generic min and max without double execution of side-effects:
   http://stackoverflow.com/questions/3437404/min-and-max-in-c
 */
 
-#define _CHOOSE(boolop, a, b, uid) \
-  ({                               \
-    decltype(a) _a_ ## uid = (a);  \
-    decltype(b) _b_ ## uid = (b);  \
-    (a) boolop (b) ? (a) : (b);    \
+#define _CHOOSE(boolop, a, b, uid)                                  \
+  ({                                                                \
+    decltype(a) _a_ ## uid = (a);                                   \
+    decltype(b) _b_ ## uid = (b);                                   \
+    (_a_ ## uid) boolop (_b_ ## uid) ? (_a_ ## uid) : (_b_ ## uid); \
   })
 #undef MIN
 #undef MAX