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