| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <string> |
| |
| // template<class charT, class traits, class Allocator> |
| // basic_ostream<charT, traits>& |
| // operator<<(basic_ostream<charT, traits>& os, |
| // const basic_string_view<charT,traits> str); |
| |
| #include <string_view> |
| #include <iosfwd> |
| |
| template <class SV, class = void> |
| struct HasDecl : std::false_type {}; |
| template <class SV> |
| struct HasDecl<SV, decltype(static_cast<void>(std::declval<std::ostream&>() << std::declval<SV&>()))> : std::true_type {}; |
| |
| int main() { |
| static_assert(HasDecl<std::string_view>::value, "streaming operator declaration not present"); |
| } |