1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14) 10 11 // <string_view> 12 13 // template<class charT, class traits, class Allocator> 14 // basic_ostream<charT, traits>& 15 // operator<<(basic_ostream<charT, traits>& os, 16 // const basic_string_view<charT,traits> str); 17 18 #include <string_view> 19 #include <iosfwd> 20 21 template <class SV, class = void> 22 struct HasDecl : std::false_type {}; 23 template <class SV> 24 struct HasDecl<SV, decltype(static_cast<void>(std::declval<std::ostream&>() << std::declval<SV&>()))> : std::true_type {}; 25 26 static_assert(HasDecl<std::string_view>::value, "streaming operator declaration not present"); 27