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 _CharT& operator[](size_type _pos) const; 14 15 #include <string_view> 16 #include <cassert> 17 18 #include "test_macros.h" 19 20 template <typename CharT> 21 void test ( const CharT *s, size_t len ) { 22 typedef std::basic_string_view<CharT> SV; 23 SV sv ( s, len ); 24 ASSERT_SAME_TYPE(decltype(sv[0]), typename SV::const_reference); 25 LIBCPP_ASSERT_NOEXCEPT( sv[0]); 26 assert ( sv.length() == len ); 27 for ( size_t i = 0; i < len; ++i ) { 28 assert ( sv[i] == s[i] ); 29 assert ( &sv[i] == s + i ); 30 } 31 } 32 33 int main(int, char**) { 34 test ( "ABCDE", 5 ); 35 test ( "a", 1 ); 36 37 test ( L"ABCDE", 5 ); 38 test ( L"a", 1 ); 39 40 #if TEST_STD_VER >= 11 41 test ( u"ABCDE", 5 ); 42 test ( u"a", 1 ); 43 44 test ( U"ABCDE", 5 ); 45 test ( U"a", 1 ); 46 #endif 47 48 #if TEST_STD_VER > 11 49 { 50 constexpr std::basic_string_view<char> sv ( "ABC", 2 ); 51 static_assert ( sv.length() == 2, "" ); 52 static_assert ( sv[0] == 'A', "" ); 53 static_assert ( sv[1] == 'B', "" ); 54 } 55 #endif 56 57 return 0; 58 } 59