-cmake_push_check_state()
-if(WIN32)
- set(CMAKE_EXTRA_INCLUDE_FILES sys/types.h ws2tcpip.h)
- check_symbol_exists(AF_INET6 "sys/types.h;ws2tcpip.h" HAVE_AF_INET6)
-else(WIN32)
- set(CMAKE_EXTRA_INCLUDE_FILES sys/types.h sys/socket.h netinet/in.h)
- check_symbol_exists(AF_INET6 "sys/types.h;sys/socket.h;netinet/in.h" HAVE_AF_INET6)
-endif(WIN32)