cmake HAVE_COMPLEX_C99_EXT examples

Kitware/VTK ThirdParty/cgns/vtkcgns/src/CMakeLists.txt :137 

check_c_source_compiles("
#include <complex.h>
int main(int argc, char *argv[]){
#if !defined(_MSC_VER)
float _Complex a[2];
__real__(a[1]) = (float) 1.0;
__imag__(a[1]) = (float) 0.0;
#endif
return 0;
}
"
  HAVE_COMPLEX_C99_EXT
)

CGNS/CGNS src/CMakeLists.txt :132 

check_c_source_compiles("
#include <complex.h>
int main(int argc, char *argv[]){
#if !defined(_MSC_VER)
float _Complex a[2];
__real__(a[1]) = (float) 1.0;
__imag__(a[1]) = (float) 0.0;
#endif
return 0;
}
"
  HAVE_COMPLEX_C99_EXT
)