kiwano::details::IsCallableHelper< _Ty, _Ret, _Args > 模板结构体 参考

类
struct	ClassConstMember
struct	ClassMember

静态 Public 成员函数
template<typename _Uty >
static int	Test (...)
template<typename _Uty >
static char	Test (ClassMember< _Uty, &_Uty::operator()> *)
template<typename _Uty >
static char	Test (ClassConstMember< _Uty, &_Uty::operator()> *)
template<typename _Uty , typename _Uret = typename std::decay<decltype(std::declval<_Uty>().operator()(std::declval<_Args>()...))>::type, typename = typename std::enable_if<std::is_convertible<_Ret, _Uret>::value>::type>
static char	Test (int)

静态 Public 属性
static constexpr bool	value = sizeof(Test<_Ty>(0)) == sizeof(char)