cmake HAVE_COPYSIGN examples

LiangliangNan/MVStudio 3rd_party/nlopt/CMakeLists.txt :123 

check_function_exists (copysign HAVE_COPYSIGN)

stevengj/nlopt CMakeLists.txt :100 

check_function_exists (copysign HAVE_COPYSIGN)

InsightSoftwareConsortium/ITK Modules/ThirdParty/MINC/src/libminc/CMakeLists.txt :148 

CHECK_SYMBOL_EXISTS(copysign "math.h" HAVE_COPYSIGN)

NVIDIA/cuda-quantum runtime/cudaq/algorithms/optimizers/nlopt/nlopt-src/CMakeLists.txt :50 

check_function_exists (copysign HAVE_COPYSIGN)

GenericMappingTools/gmt cmake/modules/ConfigureChecks.cmake :362 

check_symbol_exists (copysign    "${_math_h}" HAVE_COPYSIGN)

gazebosim/gazebo-classic deps/opende/CMakeLists.txt :42 

CHECK_CXX_SOURCE_COMPILES("#include <math.h> 
int main() {copysign(0,0); return 1;}" HAVE_COPYSIGN)