From f6b81125b340e00129978f2c9eebfba6a4d25692 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Thu, 18 Aug 2022 16:05:22 -0700
Subject: [PATCH] Always define SDL_COMPILE_TIME_ASSERT as static_assert() in
 C++

Apparently some versions of gcc will define __STDC_VERSION__ even when compiling in C++ mode.

Fixes https://github.com/libsdl-org/SDL/issues/6078
---
 include/SDL_stdinc.h | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/SDL_stdinc.h b/include/SDL_stdinc.h
index 03845b678..5f79c95b3 100644
--- a/include/SDL_stdinc.h
+++ b/include/SDL_stdinc.h
@@ -373,14 +373,22 @@ typedef uint64_t Uint64;
 #endif
 #endif /* SDL_DISABLE_ANALYZE_MACROS */
 
-#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
-#define SDL_COMPILE_TIME_ASSERT(name, x) _Static_assert(x, #x)
-#elif defined(__cplusplus) && (__cplusplus >= 201103L)
+#ifndef SDL_COMPILE_TIME_ASSERT
+#if defined(__cplusplus)
+#if (__cplusplus >= 201103L)
 #define SDL_COMPILE_TIME_ASSERT(name, x)  static_assert(x, #x)
-#else /* universal, but may trigger -Wunused-local-typedefs */
+#endif
+#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
+#define SDL_COMPILE_TIME_ASSERT(name, x) _Static_assert(x, #x)
+#endif
+#endif /* !SDL_COMPILE_TIME_ASSERT */
+
+#ifndef SDL_COMPILE_TIME_ASSERT
+/* universal, but may trigger -Wunused-local-typedefs */
 #define SDL_COMPILE_TIME_ASSERT(name, x)               \
        typedef int SDL_compile_time_assert_ ## name[(x) * 2 - 1]
 #endif
+
 /** \cond */
 #ifndef DOXYGEN_SHOULD_IGNORE_THIS
 SDL_COMPILE_TIME_ASSERT(uint8, sizeof(Uint8) == 1);