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 // constexpr const_iterator begin() const; 14 15 #include <string_view> 16 #include <cassert> 17 18 #include "test_macros.h" 19 20 template <class S> 21 void 22 test(S s) 23 { 24 const S& cs = s; 25 typename S::iterator b = s.begin(); 26 typename S::const_iterator cb1 = cs.begin(); 27 typename S::const_iterator cb2 = s.cbegin(); 28 if (!s.empty()) 29 { 30 assert( *b == s[0]); 31 assert( &*b == &s[0]); 32 assert( *cb1 == s[0]); 33 assert(&*cb1 == &s[0]); 34 assert( *cb2 == s[0]); 35 assert(&*cb2 == &s[0]); 36 37 } 38 assert( b == cb1); 39 assert( b == cb2); 40 assert(cb1 == cb2); 41 } 42 43 44 int main(int, char**) 45 { 46 typedef std::string_view string_view; 47 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 48 typedef std::u8string_view u8string_view; 49 #endif 50 typedef std::u16string_view u16string_view; 51 typedef std::u32string_view u32string_view; 52 53 test(string_view ()); 54 test(u16string_view()); 55 test(u32string_view()); 56 test(string_view ( "123")); 57 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 58 test(u8string_view{u8"123"}); 59 #endif 60 #if TEST_STD_VER >= 11 61 test(u16string_view{u"123"}); 62 test(u32string_view{U"123"}); 63 #endif 64 65 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 66 typedef std::wstring_view wstring_view; 67 test(wstring_view ()); 68 test(wstring_view (L"123")); 69 #endif 70 71 #if TEST_STD_VER > 11 72 { 73 constexpr string_view sv { "123", 3 }; 74 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 75 constexpr u8string_view u8sv {u8"123", 3 }; 76 #endif 77 constexpr u16string_view u16sv {u"123", 3 }; 78 constexpr u32string_view u32sv {U"123", 3 }; 79 80 static_assert ( *sv.begin() == sv[0], "" ); 81 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 82 static_assert ( *u8sv.begin() == u8sv[0], "" ); 83 #endif 84 static_assert ( *u16sv.begin() == u16sv[0], "" ); 85 static_assert ( *u32sv.begin() == u32sv[0], "" ); 86 87 static_assert ( *sv.cbegin() == sv[0], "" ); 88 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 89 static_assert ( *u8sv.cbegin() == u8sv[0], "" ); 90 #endif 91 static_assert ( *u16sv.cbegin() == u16sv[0], "" ); 92 static_assert ( *u32sv.cbegin() == u32sv[0], "" ); 93 94 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 95 { 96 constexpr wstring_view wsv {L"123", 3 }; 97 static_assert ( *wsv.begin() == wsv[0], "" ); 98 static_assert ( *wsv.cbegin() == wsv[0], "" ); 99 } 100 #endif 101 } 102 #endif // TEST_STD_VER > 11 103 104 return 0; 105 } 106