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 // <string> 10 11 // const_iterator cbegin() const; // constexpr since C++20 12 13 #include <string> 14 #include <cassert> 15 16 #include "test_macros.h" 17 #include "min_allocator.h" 18 19 template <class S> test(const S & s)20TEST_CONSTEXPR_CXX20 void test(const S& s) { 21 typename S::const_iterator cb = s.cbegin(); 22 if (!s.empty()) { 23 assert(*cb == s[0]); 24 } 25 assert(cb == s.begin()); 26 } 27 28 template <class S> test_string()29TEST_CONSTEXPR_CXX20 void test_string() { 30 test(S()); 31 test(S("123")); 32 } 33 test()34TEST_CONSTEXPR_CXX20 bool test() { 35 test_string<std::string>(); 36 #if TEST_STD_VER >= 11 37 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >(); 38 #endif 39 40 return true; 41 } 42 main(int,char **)43int main(int, char**) { 44 test(); 45 #if TEST_STD_VER > 17 46 static_assert(test()); 47 #endif 48 49 return 0; 50 } 51