Workaround for Visual Studio not expanding __VA_ARGS__ on macro invocation

Author: danpoe

src/util/invariant.h

@@ -249,21 +249,23 @@ invariant_violated_string(
 #define __this_function__ __func__
 #endif
 
+#define EXPAND(x) x
+
 #define GET_MACRO(X1, X2, X3, X4, X5, X6, MACRO, ...) MACRO
 
 #define REDIRECT(MACRO, ...)                                                   \
   do                                                                           \
   {                                                                            \
-    GET_MACRO(                                                                 \
+    EXPAND(EXPAND(GET_MACRO(                                                                 \
       __VA_ARGS__,                                                             \
       MACRO##6,                                                                \
       MACRO##5,                                                                \
       MACRO##4,                                                                \
       MACRO##3,                                                                \
       MACRO##2,                                                                \
       MACRO##1,                                                                \
-      DUMMY_MACRO_ARG)                                                         \
-    (__VA_ARGS__);                                                             \
+      DUMMY_MACRO_ARG))                                                         \
+    (__VA_ARGS__));                                                             \
   } while(false)
 
 #define INVARIANT2(CONDITION, REASON)                                          \
@@ -308,7 +310,7 @@ invariant_violated_string(
 // Short hand macros. The variants *_STRUCTURED below allow to specify a custom
 // exception, and are equivalent to INVARIANT_STRUCTURED.
 
-#define INVARIANT(...) REDIRECT(INVARIANT, __VA_ARGS__)
+#define INVARIANT(...) EXPAND(REDIRECT(INVARIANT, __VA_ARGS__))
 
 // The condition should only contain (unmodified) inputs to the method. Inputs
 // include arguments passed to the function, as well as member variables that
@@ -322,7 +324,7 @@ invariant_violated_string(
 #define PRECONDITION2(CONDITION, DIAGNOSTICS)                                  \
   INVARIANT3(CONDITION, "Precondition", DIAGNOSTICS)
 
-#define PRECONDITION(...) REDIRECT(PRECONDITION, __VA_ARGS__)
+#define PRECONDITION(...) EXPAND(REDIRECT(PRECONDITION, __VA_ARGS__))
 
 #define PRECONDITION_STRUCTURED(CONDITION, TYPENAME, ...) \
   INVARIANT_STRUCTURED(CONDITION, TYPENAME, __VA_ARGS__)
@@ -339,7 +341,7 @@ invariant_violated_string(
 #define POSTCONDITION2(CONDITION, DIAGNOSTICS)                                 \
   INVARIANT3(CONDITION, "Postcondition", DIAGNOSTICS)
 
-#define POSTCONDITION(...) REDIRECT(POSTCONDITION, __VA_ARGS__)
+#define POSTCONDITION(...) EXPAND(REDIRECT(POSTCONDITION, __VA_ARGS__))
 
 #define POSTCONDITION_STRUCTURED(CONDITION, TYPENAME, ...) \
   INVARIANT_STRUCTURED(CONDITION, TYPENAME, __VA_ARGS__)
@@ -356,7 +358,7 @@ invariant_violated_string(
 #define CHECK_RETURN2(CONDITION, DIAGNOSTICS)                                  \
   INVARIANT3(CONDITION, "Check return value", DIAGNOSTICS)
 
-#define CHECK_RETURN(...) REDIRECT(CHECK_RETURN, __VA_ARGS__)
+#define CHECK_RETURN(...) EXPAND(REDIRECT(CHECK_RETURN, __VA_ARGS__))
 
 #define CHECK_RETURN_STRUCTURED(CONDITION, TYPENAME, ...)  \
   INVARIANT_STRUCTURED(CONDITION, TYPENAME, __VA_ARGS__)
@@ -373,7 +375,7 @@ invariant_violated_string(
 #define DATA_INVARIANT3(CONDITION, REASON, DIAGNOSTICS)                        \
   INVARIANT3(CONDITION, REASON, DIAGNOSTICS)
 
-#define DATA_INVARIANT(...) REDIRECT(DATA_INVARIANT, __VA_ARGS__)
+#define DATA_INVARIANT(...) EXPAND(REDIRECT(DATA_INVARIANT, __VA_ARGS__))
 
 #define DATA_INVARIANT_STRUCTURED(CONDITION, TYPENAME, ...) \
   INVARIANT_STRUCTURED(CONDITION, TYPENAME, __VA_ARGS__)