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 "test_macros.h" 22 #include "min_allocator.h" 23 24 template <class S> 25 void 26 test(S s) 27 { 28 const S& cs = s; 29 ASSERT_SAME_TYPE(decltype( s.back()), typename S::reference); 30 ASSERT_SAME_TYPE(decltype(cs.back()), typename S::const_reference); 31 LIBCPP_ASSERT_NOEXCEPT( s.back()); 32 LIBCPP_ASSERT_NOEXCEPT( cs.back()); 33 assert(&cs.back() == &cs[cs.size()-1]); 34 assert(&s.back() == &s[cs.size()-1]); 35 s.back() = typename S::value_type('z'); 36 assert(s.back() == typename S::value_type('z')); 37 } 38 39 int main(int, char**) 40 { 41 { 42 typedef std::string S; 43 test(S("1")); 44 test(S("1234567890123456789012345678901234567890")); 45 } 46 #if TEST_STD_VER >= 11 47 { 48 typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S; 49 test(S("1")); 50 test(S("1234567890123456789012345678901234567890")); 51 } 52 #endif 53 #ifdef _LIBCPP_DEBUG 54 { 55 std::string s; 56 (void) s.back(); 57 assert(false); 58 } 59 #endif 60 61 return 0; 62 } 63