winapi::winsock2::LPCONDITIONPROC

type LPCONDITIONPROC = Option<unsafe extern "system" fn(lpCallerId: LPWSABUF, lpCallerData: LPWSABUF, lpSQOS: LPQOS, lpGQOS: LPQOS, lpCalleeId: LPWSABUF, lpCalleeData: LPWSABUF, g: *mut GROUP, dwCallbackData: DWORD) -> c_int>;