100 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: !stdlib=libc++ && (c++03 || c++11 || c++14)10 11// <string_view>12 13// constexpr const_iterator begin() const;14 15#include <string_view>16#include <cassert>17 18#include "test_macros.h"19 20template <class S>21void test(S s) {22 const S& cs = s;23 typename S::iterator b = s.begin();24 typename S::const_iterator cb1 = cs.begin();25 typename S::const_iterator cb2 = s.cbegin();26 if (!s.empty()) {27 assert(*b == s[0]);28 assert(&*b == &s[0]);29 assert(*cb1 == s[0]);30 assert(&*cb1 == &s[0]);31 assert(*cb2 == s[0]);32 assert(&*cb2 == &s[0]);33 }34 assert(b == cb1);35 assert(b == cb2);36 assert(cb1 == cb2);37}38 39int main(int, char**) {40 typedef std::string_view string_view;41#ifndef TEST_HAS_NO_CHAR8_T42 typedef std::u8string_view u8string_view;43#endif44 typedef std::u16string_view u16string_view;45 typedef std::u32string_view u32string_view;46 47 test(string_view());48 test(u16string_view());49 test(u32string_view());50 test(string_view("123"));51#ifndef TEST_HAS_NO_CHAR8_T52 test(u8string_view{u8"123"});53#endif54#if TEST_STD_VER >= 1155 test(u16string_view{u"123"});56 test(u32string_view{U"123"});57#endif58 59#ifndef TEST_HAS_NO_WIDE_CHARACTERS60 typedef std::wstring_view wstring_view;61 test(wstring_view());62 test(wstring_view(L"123"));63#endif64 65#if TEST_STD_VER > 1166 {67 constexpr string_view sv{"123", 3};68# ifndef TEST_HAS_NO_CHAR8_T69 constexpr u8string_view u8sv{u8"123", 3};70# endif71 constexpr u16string_view u16sv{u"123", 3};72 constexpr u32string_view u32sv{U"123", 3};73 74 static_assert(*sv.begin() == sv[0], "");75# ifndef TEST_HAS_NO_CHAR8_T76 static_assert(*u8sv.begin() == u8sv[0], "");77# endif78 static_assert(*u16sv.begin() == u16sv[0], "");79 static_assert(*u32sv.begin() == u32sv[0], "");80 81 static_assert(*sv.cbegin() == sv[0], "");82# ifndef TEST_HAS_NO_CHAR8_T83 static_assert(*u8sv.cbegin() == u8sv[0], "");84# endif85 static_assert(*u16sv.cbegin() == u16sv[0], "");86 static_assert(*u32sv.cbegin() == u32sv[0], "");87 88# ifndef TEST_HAS_NO_WIDE_CHARACTERS89 {90 constexpr wstring_view wsv{L"123", 3};91 static_assert(*wsv.begin() == wsv[0], "");92 static_assert(*wsv.cbegin() == wsv[0], "");93 }94# endif95 }96#endif // TEST_STD_VER > 1197 98 return 0;99}100