conditional flatten

Author: hanickadot

include/ctre/utility.hpp

@@ -24,8 +24,12 @@
 
 #ifdef _MSC_VER
 #define CTRE_FORCE_INLINE __forceinline
+#if _MSC_VER >= 1930
 #define CTRE_FLATTEN [[msvc::flatten]]
 #else
+#define CTRE_FLATTEN
+#endif
+#else
 #define CTRE_FORCE_INLINE inline __attribute__((always_inline))
 #define CTRE_FLATTEN __attribute__((flatten))
 #endif

single-header/ctre-unicode.hpp

@@ -1408,8 +1408,12 @@ struct pcre {
 
 #ifdef _MSC_VER
 #define CTRE_FORCE_INLINE __forceinline
+#if _MSC_VER >= 1930
 #define CTRE_FLATTEN [[msvc::flatten]]
 #else
+#define CTRE_FLATTEN
+#endif
+#else
 #define CTRE_FORCE_INLINE inline __attribute__((always_inline))
 #define CTRE_FLATTEN __attribute__((flatten))
 #endif

single-header/ctre.hpp

@@ -1405,8 +1405,12 @@ struct pcre {
 
 #ifdef _MSC_VER
 #define CTRE_FORCE_INLINE __forceinline
+#if _MSC_VER >= 1930
 #define CTRE_FLATTEN [[msvc::flatten]]
 #else
+#define CTRE_FLATTEN
+#endif
+#else
 #define CTRE_FORCE_INLINE inline __attribute__((always_inline))
 #define CTRE_FLATTEN __attribute__((flatten))
 #endif