cmake HAVE_FPCLASS examples

Kitware/VTK ThirdParty/libxml2/vtklibxml2/CMakeLists.txt :184 

check_function_exists(fpclass HAVE_FPCLASS)

SCIInstitute/SCIRun src/Externals/libxml2/CMakeLists.txt :147 

CHECK_FUNCTION_EXISTS("fpclass" HAVE_FPCLASS)