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 resize(size_type n); // constexpr since C++20 12 13 #include <string> 14 #include <stdexcept> 15 #include <cassert> 16 17 #include "test_macros.h" 18 #include "min_allocator.h" 19 20 template <class S> 21 TEST_CONSTEXPR_CXX20 void 22 test(S s, typename S::size_type n, S expected) 23 { 24 if (n <= s.max_size()) 25 { 26 s.resize(n); 27 LIBCPP_ASSERT(s.__invariants()); 28 assert(s == expected); 29 } 30 #ifndef TEST_HAS_NO_EXCEPTIONS 31 else if (!TEST_IS_CONSTANT_EVALUATED) 32 { 33 try 34 { 35 s.resize(n); 36 assert(false); 37 } 38 catch (std::length_error&) 39 { 40 assert(n > s.max_size()); 41 } 42 } 43 #endif 44 } 45 46 template <class S> 47 TEST_CONSTEXPR_CXX20 void test_string() { 48 test(S(), 0, S()); 49 test(S(), 1, S(1, '\0')); 50 test(S(), 10, S(10, '\0')); 51 test(S(), 100, S(100, '\0')); 52 test(S("12345"), 0, S()); 53 test(S("12345"), 2, S("12")); 54 test(S("12345"), 5, S("12345")); 55 test(S("12345"), 15, S("12345\0\0\0\0\0\0\0\0\0\0", 15)); 56 test(S("12345678901234567890123456789012345678901234567890"), 0, S()); 57 test(S("12345678901234567890123456789012345678901234567890"), 10, 58 S("1234567890")); 59 test(S("12345678901234567890123456789012345678901234567890"), 50, 60 S("12345678901234567890123456789012345678901234567890")); 61 test(S("12345678901234567890123456789012345678901234567890"), 60, 62 S("12345678901234567890123456789012345678901234567890\0\0\0\0\0\0\0\0\0\0", 60)); 63 test(S(), S::npos, S("not going to happen")); 64 } 65 66 TEST_CONSTEXPR_CXX20 bool test() { 67 test_string<std::string>(); 68 #if TEST_STD_VER >= 11 69 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>(); 70 #endif 71 72 return true; 73 } 74 75 int main(int, char**) 76 { 77 test(); 78 #if TEST_STD_VER > 17 79 static_assert(test()); 80 #endif 81 82 return 0; 83 } 84