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: !stdlib=libc++ && (c++03 || c++11 || c++14) 10 11 // <string_view> 12 13 // constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const; 14 15 // Throws: out_of_range if pos > size(). 16 // Effects: Determines the effective length rlen of the string to reference as the smaller of n and size() - pos. 17 // Returns: basic_string_view(data()+pos, rlen). 18 19 #include <algorithm> 20 #include <cassert> 21 #include <cstddef> 22 #include <stdexcept> 23 #include <string_view> 24 25 #include "test_macros.h" 26 27 template <typename CharT> 28 void test1(std::basic_string_view<CharT> sv, std::size_t n, size_t pos) { 29 std::basic_string_view<CharT> sv1; 30 #ifdef TEST_HAS_NO_EXCEPTIONS 31 if (pos > sv.size()) 32 return; // would throw if exceptions were enabled 33 sv1 = sv.substr(pos, n); 34 #else 35 try { 36 sv1 = sv.substr(pos, n); 37 assert(pos <= sv.size()); 38 } catch (const std::out_of_range&) { 39 assert(pos > sv.size()); 40 return; 41 } 42 #endif 43 const std::size_t rlen = std::min(n, sv.size() - pos); 44 assert(sv1.size() == rlen); 45 for (std::size_t i = 0; i < rlen; ++i) 46 assert(sv[pos + i] == sv1[i]); 47 } 48 49 template <typename CharT> 50 void test(const CharT* s) { 51 typedef std::basic_string_view<CharT> string_view_t; 52 53 string_view_t sv1(s); 54 55 test1(sv1, 0, 0); 56 test1(sv1, 1, 0); 57 test1(sv1, 20, 0); 58 test1(sv1, sv1.size(), 0); 59 60 test1(sv1, 0, 3); 61 test1(sv1, 2, 3); 62 test1(sv1, 100, 3); 63 64 test1(sv1, 0, string_view_t::npos); 65 test1(sv1, 2, string_view_t::npos); 66 test1(sv1, sv1.size(), string_view_t::npos); 67 68 test1(sv1, sv1.size() + 1, 0); 69 test1(sv1, sv1.size() + 1, 1); 70 test1(sv1, sv1.size() + 1, string_view_t::npos); 71 } 72 73 int main(int, char**) { 74 test("ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE"); 75 test("ABCDE"); 76 test("a"); 77 test(""); 78 79 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 80 test(L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE"); 81 test(L"ABCDE"); 82 test(L"a"); 83 test(L""); 84 #endif 85 86 #if TEST_STD_VER >= 11 87 test(u"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE"); 88 test(u"ABCDE"); 89 test(u"a"); 90 test(u""); 91 92 test(U"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE"); 93 test(U"ABCDE"); 94 test(U"a"); 95 test(U""); 96 #endif 97 98 #if TEST_STD_VER > 11 99 { 100 constexpr std::string_view sv1{"ABCDE", 5}; 101 102 { 103 constexpr std::string_view sv2 = sv1.substr(0, 3); 104 static_assert(sv2.size() == 3, ""); 105 static_assert(sv2[0] == 'A', ""); 106 static_assert(sv2[1] == 'B', ""); 107 static_assert(sv2[2] == 'C', ""); 108 } 109 110 { 111 constexpr std::string_view sv2 = sv1.substr(3, 0); 112 static_assert(sv2.size() == 0, ""); 113 } 114 115 { 116 constexpr std::string_view sv2 = sv1.substr(3, 3); 117 static_assert(sv2.size() == 2, ""); 118 static_assert(sv2[0] == 'D', ""); 119 static_assert(sv2[1] == 'E', ""); 120 } 121 } 122 #endif 123 124 return 0; 125 } 126