61 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// <sstream>12 13// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >14// class basic_ostringstream15 16// basic_string_view<charT, traits> view() const noexcept;17 18#include <sstream>19#include <cassert>20#include <type_traits>21 22#include "make_string.h"23#include "test_macros.h"24 25#define STR(S) MAKE_STRING(CharT, S)26#define SV(S) MAKE_STRING_VIEW(CharT, S)27 28template <class CharT>29struct my_char_traits : public std::char_traits<CharT> {};30 31template <class CharT>32static void test() {33 std::basic_ostringstream<CharT> ss(STR(" 123 456"));34 static_assert(noexcept(ss.view()));35 assert(ss.view() == SV(" 123 456"));36 int i = 0;37 ss << i;38 assert(ss.view() == SV("0123 456"));39 ss << 456;40 assert(ss.view() == SV("0456 456"));41 ss.str(STR(" 789"));42 assert(ss.view() == SV(" 789"));43 ss << SV("abc");44 assert(ss.view() == SV("abc9"));45 46 const std::basic_ostringstream<CharT> css(STR("abc"));47 static_assert(noexcept(css.view()));48 assert(css.view() == SV("abc"));49 50 std::basic_ostringstream<CharT, my_char_traits<CharT>> tss;51 static_assert(std::is_same_v<decltype(tss.view()), std::basic_string_view<CharT, my_char_traits<CharT>>>);52}53 54int main(int, char**) {55 test<char>();56#ifndef TEST_HAS_NO_WIDE_CHARACTERS57 test<wchar_t>();58#endif59 return 0;60}61