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: c++03 10 11 // <string> 12 13 // ~basic_string() // implied noexcept; // constexpr since C++20 14 15 #include <string> 16 #include <cassert> 17 18 #include "test_macros.h" 19 #include "test_allocator.h" 20 21 template <class T> 22 struct throwing_alloc 23 { 24 typedef T value_type; 25 throwing_alloc(const throwing_alloc&); 26 T *allocate(size_t); 27 ~throwing_alloc() noexcept(false); 28 }; 29 30 // Test that it's possible to take the address of basic_string's destructors 31 // by creating globals which will register their destructors with cxa_atexit. 32 std::string s; 33 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 34 std::wstring ws; 35 #endif 36 37 static_assert(std::is_nothrow_destructible<std::string>::value, ""); 38 static_assert(std::is_nothrow_destructible< 39 std::basic_string<char, std::char_traits<char>, test_allocator<char>>>::value, ""); 40 LIBCPP_STATIC_ASSERT(!std::is_nothrow_destructible< 41 std::basic_string<char, std::char_traits<char>, throwing_alloc<char>>>::value, ""); 42 43 TEST_CONSTEXPR_CXX20 bool test() { 44 test_allocator_statistics alloc_stats; 45 { 46 std::basic_string<char, std::char_traits<char>, test_allocator<char>> str2((test_allocator<char>(&alloc_stats))); 47 str2 = "long long string so no SSO"; 48 assert(alloc_stats.alloc_count == 1); 49 } 50 assert(alloc_stats.alloc_count == 0); 51 52 return true; 53 } 54 55 int main(int, char**) 56 { 57 test(); 58 #if TEST_STD_VER > 17 59 static_assert(test()); 60 #endif 61 62 return 0; 63 } 64