126 lines · cpp
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-exception6//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 27template <typename CharT>28void 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_EXCEPTIONS31 if (pos > sv.size())32 return; // would throw if exceptions were enabled33 sv1 = sv.substr(pos, n);34#else35 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#endif43 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 49template <typename CharT>50void 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 73int main(int, char**) {74 test("ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");75 test("ABCDE");76 test("a");77 test("");78 79#ifndef TEST_HAS_NO_WIDE_CHARACTERS80 test(L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");81 test(L"ABCDE");82 test(L"a");83 test(L"");84#endif85 86#if TEST_STD_VER >= 1187 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#endif97 98#if TEST_STD_VER > 1199 {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#endif123 124 return 0;125}126