improve EN/DISABLEIF macros to support complex templated parameters

build/Doxyfile

@@ -1993,7 +1993,9 @@ INCLUDE_FILE_PATTERNS  =
 
 PREDEFINED             = \
 	RAPIDJSON_DOXYGEN_RUNNING \
-	RAPIDJSON_DISABLEIF_RETURN(cond,returntype)=returntype
+	RAPIDJSON_REMOVEFPTR_(x)=x \
+	RAPIDJSON_ENABLEIF_RETURN(cond,returntype)="RAPIDJSON_REMOVEFPTR_ returntype" \
+	RAPIDJSON_DISABLEIF_RETURN(cond,returntype)="RAPIDJSON_REMOVEFPTR_ returntype"
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The

include/rapidjson/document.h

@@ -588,7 +588,7 @@ public:
             use \ref SetBool() instead.
     */
     template <typename T>
-    RAPIDJSON_DISABLEIF_RETURN(internal::IsPointer<T>,GenericValue&)
+    RAPIDJSON_DISABLEIF_RETURN((internal::IsPointer<T>), (GenericValue&))
     operator=(T value) {
         GenericValue v(value);
         return *this = v;
@@ -683,7 +683,7 @@ public:
     //! Equal-to operator with primitive types
     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t, \c double, \c true, \c false
     */
-    template <typename T> RAPIDJSON_DISABLEIF_RETURN(internal::IsPointer<T>, bool) operator==(const T& rhs) const { return *this == GenericValue(rhs); }
+    template <typename T> RAPIDJSON_DISABLEIF_RETURN((internal::IsPointer<T>), (bool)) operator==(const T& rhs) const { return *this == GenericValue(rhs); }
 
     //! Not-equal-to operator
     /*! \return !(*this == rhs)
@@ -934,7 +934,7 @@ public:
         \note Amortized Constant time complexity.
     */
     template <typename T>
-    RAPIDJSON_DISABLEIF_RETURN(internal::IsPointer<T>,GenericValue&)
+    RAPIDJSON_DISABLEIF_RETURN((internal::IsPointer<T>), (GenericValue&))
     AddMember(StringRefType name, T value, Allocator& allocator) {
         GenericValue n(name);
         GenericValue v(value);
@@ -1147,7 +1147,7 @@ int z = a[0u].GetInt();             // This works too.
         \note Amortized constant time complexity.
     */
     template <typename T>
-    RAPIDJSON_DISABLEIF_RETURN(internal::IsPointer<T>,GenericValue&)
+    RAPIDJSON_DISABLEIF_RETURN((internal::IsPointer<T>), (GenericValue&))
     PushBack(T value, Allocator& allocator) {
         GenericValue v(value);
         return PushBack(v, allocator);

include/rapidjson/internal/meta.h

@@ -66,6 +66,9 @@ struct IsMoreConst {
     };
 };
 
+//////////////////////////////////////////////////////////////////////////
+// EnableIf / DisableIf
+//
 template <bool Condition, typename T = void> struct EnableIfCond;
 template <typename T> struct EnableIfCond<true, T> { typedef T Type; };
 template <typename T> struct EnableIfCond<false, T> { /* empty */ };
@@ -92,8 +95,19 @@ template <typename T> struct RemoveSfinaeFptr<SfinaeResultTag&(*)(T)> { typedef
     typename ::rapidjson::internal::EnableIf \
         <RAPIDJSON_REMOVEFPTR_(cond)>::Type * = NULL
 
+#define RAPIDJSON_DISABLEIF(cond) \
+    typename ::rapidjson::internal::DisableIf \
+        <RAPIDJSON_REMOVEFPTR_(cond)>::Type * = NULL
+
+#define RAPIDJSON_ENABLEIF_RETURN(cond,returntype) \
+    typename ::rapidjson::internal::EnableIf \
+        <RAPIDJSON_REMOVEFPTR_(cond), \
+         RAPIDJSON_REMOVEFPTR_(returntype)>::Type
+
 #define RAPIDJSON_DISABLEIF_RETURN(cond,returntype) \
-    typename ::rapidjson::internal::DisableIf<cond,returntype>::Type
+    typename ::rapidjson::internal::DisableIf \
+        <RAPIDJSON_REMOVEFPTR_(cond), \
+         RAPIDJSON_REMOVEFPTR_(returntype)>::Type
 
 } // namespace internal
 } // namespace rapidjson