diff options
Diffstat (limited to 'libcxx/include/variant')
-rw-r--r-- | libcxx/include/variant | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/libcxx/include/variant b/libcxx/include/variant index 5d0722b6296..baf163050dd 100644 --- a/libcxx/include/variant +++ b/libcxx/include/variant @@ -1098,11 +1098,39 @@ struct __overload<> { void operator()() const; }; template <class _Tp, class... _Types> struct __overload<_Tp, _Types...> : __overload<_Types...> { using __overload<_Types...>::operator(); - __identity<_Tp> operator()(_Tp) const; + + static auto __test(_Tp (&&)[1]) -> __identity<_Tp>; + + template <class _Up> + auto operator()(_Tp, _Up&& __t) const + -> decltype(__test({ _VSTD::forward<_Up>(__t) })); +}; + +template <class _Base, class _Tp> +struct __overload_bool : _Base { + using _Base::operator(); + + template <class _Up, class _Ap = __uncvref_t<_Up>> + auto operator()(bool, _Up&&) const + -> enable_if_t<is_same_v<_Ap, bool>, __identity<_Tp>>; }; +template <class... _Types> +struct __overload<bool, _Types...> + : __overload_bool<__overload<_Types...>, bool> {}; +template <class... _Types> +struct __overload<bool const, _Types...> + : __overload_bool<__overload<_Types...>, bool const> {}; +template <class... _Types> +struct __overload<bool volatile, _Types...> + : __overload_bool<__overload<_Types...>, bool volatile> {}; +template <class... _Types> +struct __overload<bool const volatile, _Types...> + : __overload_bool<__overload<_Types...>, bool const volatile> {}; + template <class _Tp, class... _Types> -using __best_match_t = typename result_of_t<__overload<_Types...>(_Tp&&)>::type; +using __best_match_t = + typename invoke_result_t<__overload<_Types...>, _Tp, _Tp>::type; } // __variant_detail |