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 charT& back() const; 12 // charT& back(); 13 14 #ifdef _LIBCPP_DEBUG 15 #define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0)) 16 #endif 17 18 #include <string> 19 #include <cassert> 20 21 #include "min_allocator.h" 22 23 template <class S> 24 void 25 test(S s) 26 { 27 const S& cs = s; 28 ASSERT_SAME_TYPE(decltype( s.back()), typename S::reference); 29 ASSERT_SAME_TYPE(decltype(cs.back()), typename S::const_reference); 30 LIBCPP_ASSERT_NOEXCEPT( s.back()); 31 LIBCPP_ASSERT_NOEXCEPT( cs.back()); 32 assert(&cs.back() == &cs[cs.size()-1]); 33 assert(&s.back() == &s[cs.size()-1]); 34 s.back() = typename S::value_type('z'); 35 assert(s.back() == typename S::value_type('z')); 36 } 37 38 int main(int, char**) 39 { 40 { 41 typedef std::string S; 42 test(S("1")); 43 test(S("1234567890123456789012345678901234567890")); 44 } 45 #if TEST_STD_VER >= 11 46 { 47 typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S; 48 test(S("1")); 49 test(S("1234567890123456789012345678901234567890")); 50 } 51 #endif 52 #ifdef _LIBCPP_DEBUG 53 { 54 std::string s; 55 char c = s.back(); 56 assert(false); 57 } 58 #endif 59 60 return 0; 61 } 62