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 // void shrink_to_fit(); // 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> 20 TEST_CONSTEXPR_CXX20 void 21 test(S s) 22 { 23 typename S::size_type old_cap = s.capacity(); 24 S s0 = s; 25 s.shrink_to_fit(); 26 LIBCPP_ASSERT(s.__invariants()); 27 assert(s == s0); 28 assert(s.capacity() <= old_cap); 29 assert(s.capacity() >= s.size()); 30 } 31 32 TEST_CONSTEXPR_CXX20 bool test() { 33 { 34 typedef std::string S; 35 S s; 36 test(s); 37 38 s.assign(10, 'a'); 39 s.erase(5); 40 test(s); 41 42 s.assign(100, 'a'); 43 s.erase(50); 44 test(s); 45 } 46 #if TEST_STD_VER >= 11 47 { 48 typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S; 49 S s; 50 test(s); 51 52 s.assign(10, 'a'); 53 s.erase(5); 54 test(s); 55 56 s.assign(100, 'a'); 57 s.erase(50); 58 test(s); 59 } 60 #endif 61 62 return true; 63 } 64 65 int main(int, char**) 66 { 67 test(); 68 #if TEST_STD_VER > 17 69 static_assert(test()); 70 #endif 71 72 return 0; 73 } 74