Tests/CompileFeatures/C_STANDARD_17.c - third_party/github.com/Kitware/CMake - Git at Google

 #include "c_std.h"
 #if defined(C_STD) && C_STD > C_STD_17
 #  error "C_STANDARD 17 honored as higher standard"
 #endif
 #if defined(C_STD) && C_STD <= C_STD_11
 #  error "C_STANDARD 17 not honored"
 #endif
	#include "c_std.h"
	#if defined(C_STD) && C_STD > C_STD_17
	# error "C_STANDARD 17 honored as higher standard"
	#endif
	#if defined(C_STD) && C_STD <= C_STD_11
	# error "C_STANDARD 17 not honored"
	#endif