diff options
Diffstat (limited to 'libstdc++-v3/include/std/ranges')
| -rw-r--r-- | libstdc++-v3/include/std/ranges | 39 |
1 files changed, 29 insertions, 10 deletions
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 3e71ecb32b7..443fe65da92 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -671,30 +671,41 @@ namespace views template<typename _Tp> inline constexpr empty_view<_Tp> empty{}; - struct _Single + namespace __detail { template<typename _Tp> - [[nodiscard]] + concept __can_single_view + = requires { single_view<decay_t<_Tp>>(std::declval<_Tp>()); }; + } // namespace __detail + + struct _Single + { + template<__detail::__can_single_view _Tp> constexpr auto - operator()(_Tp&& __e) const + operator() [[nodiscard]] (_Tp&& __e) const noexcept(noexcept(single_view<decay_t<_Tp>>(std::forward<_Tp>(__e)))) { return single_view<decay_t<_Tp>>(std::forward<_Tp>(__e)); } }; inline constexpr _Single single{}; + namespace __detail + { + template<typename... _Args> + concept __can_iota_view = requires { iota_view(std::declval<_Args>()...); }; + } // namespace __detail + struct _Iota { - template<typename _Tp> - [[nodiscard]] + template<__detail::__can_iota_view _Tp> constexpr auto - operator()(_Tp&& __e) const + operator() [[nodiscard]] (_Tp&& __e) const { return iota_view(std::forward<_Tp>(__e)); } template<typename _Tp, typename _Up> - [[nodiscard]] + requires __detail::__can_iota_view<_Tp, _Up> constexpr auto - operator()(_Tp&& __e, _Up&& __f) const + operator() [[nodiscard]] (_Tp&& __e, _Up&& __f) const { return iota_view(std::forward<_Tp>(__e), std::forward<_Up>(__f)); } }; @@ -791,13 +802,21 @@ namespace views namespace views { + namespace __detail + { + template<typename _Tp, typename _Up> + concept __can_istream_view = requires (_Up __e) { + basic_istream_view<_Tp, typename _Up::char_type, typename _Up::traits_type>(__e); + }; + } // namespace __detail + template<typename _Tp> struct _Istream { template<typename _CharT, typename _Traits> - [[nodiscard]] constexpr auto - operator()(basic_istream<_CharT, _Traits>& __e) const + operator() [[nodiscard]] (basic_istream<_CharT, _Traits>& __e) const + requires __detail::__can_istream_view<_Tp, remove_reference_t<decltype(__e)>> { return basic_istream_view<_Tp, _CharT, _Traits>(__e); } }; |