151 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: c++03, c++11, c++14, c++17, c++2010 11// template<container-compatible-range<charT> R>12// constexpr basic_string(from_range_t, R&& rg, const Allocator& a = Allocator()); // since C++2313 14#include <algorithm>15#include <sstream>16#include <string>17#include <utility>18#include <vector>19 20#include "../../../containers/from_range_helpers.h"21#include "../../../containers/sequences/from_range_sequence_containers.h"22#include "test_macros.h"23#include "asan_testing.h"24 25template <class Container, class Range, class Alloc>26concept StringHasFromRangeAllocCtr =27 requires(Range&& range, const Alloc& alloc) { Container(std::from_range, std::forward<Range>(range), alloc); };28 29constexpr bool test_constraints() {30 // (from_range, range)31 //32 // Input range with the same value type.33 static_assert(HasFromRangeCtr<std::string, InputRange<char>>);34 // Input range with a convertible value type.35 static_assert(HasFromRangeCtr<std::string, InputRange<int>>);36 // Input range with a non-convertible value type.37 static_assert(!HasFromRangeCtr<std::string, InputRange<Empty>>);38 // Not an input range.39 static_assert(!HasFromRangeCtr<std::string, InputRangeNotDerivedFrom>);40 static_assert(!HasFromRangeCtr<std::string, InputRangeNotIndirectlyReadable>);41 static_assert(!HasFromRangeCtr<std::string, InputRangeNotInputOrOutputIterator>);42 43 // (from_range, range, alloc)44 //45 // Input range with the same value type.46 using Alloc = test_allocator<char>;47 using StringWithAlloc = std::basic_string<char, std::char_traits<char>, Alloc>;48 static_assert(StringHasFromRangeAllocCtr<StringWithAlloc, InputRange<char>, Alloc>);49 // Input range with a convertible value type.50 static_assert(StringHasFromRangeAllocCtr<StringWithAlloc, InputRange<int>, Alloc>);51 // Input range with a non-convertible value type.52 static_assert(!StringHasFromRangeAllocCtr<StringWithAlloc, InputRange<Empty>, Alloc>);53 // Not an input range.54 static_assert(!StringHasFromRangeAllocCtr<StringWithAlloc, InputRangeNotDerivedFrom, Alloc>);55 static_assert(!StringHasFromRangeAllocCtr<StringWithAlloc, InputRangeNotIndirectlyReadable, Alloc>);56 static_assert(!StringHasFromRangeAllocCtr<StringWithAlloc, InputRangeNotInputOrOutputIterator, Alloc>);57 // Not an allocator.58 static_assert(!StringHasFromRangeAllocCtr<StringWithAlloc, InputRange<char>, Empty>);59 60 return true;61}62 63template <class Iter, class Sent, class Alloc>64constexpr void test_with_input(std::vector<char> input) {65 { // (range)66 std::ranges::subrange in(Iter(input.data()), Sent(Iter(input.data() + input.size())));67 std::string c(std::from_range, in);68 69 LIBCPP_ASSERT(c.__invariants());70 assert(c.size() == static_cast<std::size_t>(std::distance(c.begin(), c.end())));71 assert(std::ranges::equal(input, c));72 LIBCPP_ASSERT(is_string_asan_correct(c));73 }74 75 { // (range, allocator)76 std::ranges::subrange in(Iter(input.data()), Sent(Iter(input.data() + input.size())));77 Alloc alloc;78 std::basic_string<char, std::char_traits<char>, Alloc> c(std::from_range, in, alloc);79 80 LIBCPP_ASSERT(c.__invariants());81 assert(c.get_allocator() == alloc);82 assert(c.size() == static_cast<std::size_t>(std::distance(c.begin(), c.end())));83 assert(std::ranges::equal(input, c));84 LIBCPP_ASSERT(is_string_asan_correct(c));85 }86 87 { // Ensure input-only sized ranges are accepted.88 using input_iter = cpp20_input_iterator<const char*>;89 const char in[]{'q', 'w', 'e', 'r'};90 std::string s(std::from_range, std::views::counted(input_iter{std::ranges::begin(in)}, std::ranges::ssize(in)));91 assert(s == "qwer");92 }93}94 95void test_string_exception_safety_throwing_allocator() {96#if !defined(TEST_HAS_NO_EXCEPTIONS)97 try {98 ThrowingAllocator<char> alloc;99 100 globalMemCounter.reset();101 // Note: the input string must be long enough to prevent SSO, otherwise the allocator won't be used.102 std::basic_string<char, std::char_traits<char>, ThrowingAllocator<char>> c(103 std::from_range, std::vector<char>(64, 'A'), alloc);104 assert(false); // The constructor call should throw.105 106 } catch (int) {107 assert(globalMemCounter.new_called == globalMemCounter.delete_called);108 }109#endif110}111 112constexpr bool test_inputs() {113 for_all_iterators_and_allocators<char>([]<class Iter, class Sent, class Alloc>() {114 // Shorter input -- SSO.115 test_with_input<Iter, Sent, Alloc>({'a', 'b', 'c', 'd', 'e'});116 // Longer input -- no SSO.117 test_with_input<Iter, Sent, Alloc>(std::vector<char>(64, 'A'));118 // Empty input.119 test_with_input<Iter, Sent, Alloc>({});120 // Single-element input.121 test_with_input<Iter, Sent, Alloc>({'a'});122 });123 124 return true;125}126 127#ifndef TEST_HAS_NO_LOCALIZATION128void test_counted_istream_view() {129 std::istringstream is{"qwert"};130 auto vals = std::views::istream<char>(is);131 std::string s(std::from_range, std::views::counted(vals.begin(), 3));132 assert(s == "qwe");133}134#endif135 136int main(int, char**) {137 test_inputs();138 static_assert(test_inputs());139 140 static_assert(test_constraints());141 142 // Note: `test_exception_safety_throwing_copy` doesn't apply because copying a `char` cannot throw.143 test_string_exception_safety_throwing_allocator();144 145#ifndef TEST_HAS_NO_LOCALIZATION146 test_counted_istream_view();147#endif148 149 return 0;150}151