cmake HAVE_DECL_OPTARG examples

Kitware/VTK ThirdParty/tiff/vtktiff/cmake/SymbolChecks.cmake :32 

check_symbol_exists(optarg "getopt.h" HAVE_DECL_OPTARG)

InsightSoftwareConsortium/ITK Modules/ThirdParty/TIFF/src/itktiff/cmake/SymbolChecks.cmake :32 

check_symbol_exists(optarg "getopt.h" HAVE_DECL_OPTARG)

alibaba/AliSQLBackup storage/innobase/xtrabackup/src/libarchive/CMakeLists.txt :553 

CHECK_SYMBOL_EXISTS(optarg           "unistd.h"   HAVE_DECL_OPTARG)

Ravbug/UnityHubNative wxWidgets/src/tiff/cmake/SymbolChecks.cmake :32 

check_symbol_exists(optarg "getopt.h" HAVE_DECL_OPTARG)