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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <string>
// UNSUPPORTED: c++03, c++11, c++14
// template<class InputIterator,
// class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
// basic_string(InputIterator, InputIterator, Allocator = Allocator())
// -> basic_string<typename iterator_traits<InputIterator>::value_type,
// char_traits<typename iterator_traits<InputIterator>::value_type>,
// Allocator>; // constexpr since C++20
//
// The deduction guide shall not participate in overload resolution if InputIterator
// is a type that does not qualify as an input iterator, or if Allocator is a type
// that does not qualify as an allocator.
#include <cassert>
#include <cstddef>
#include <iterator>
#include <string>
#include <type_traits>
#include "test_macros.h"
#include "test_allocator.h"
#include "min_allocator.h"
class NotAnIterator {};
using NotAnInputIterator = std::back_insert_iterator<std::basic_string<char16_t>>;
template <typename T>
struct NotAnAllocator { typedef T value_type; };
template <class Iter, class Alloc, class = void>
struct CanDeduce : std::false_type { };
template <class Iter, class Alloc>
struct CanDeduce<Iter, Alloc, decltype((void)
std::basic_string{std::declval<Iter>(), std::declval<Iter>(), std::declval<Alloc>()}
)> : std::true_type { };
static_assert( CanDeduce<int*, std::allocator<int>>::value);
static_assert(!CanDeduce<NotAnIterator, std::allocator<char>>::value);
static_assert(!CanDeduce<NotAnInputIterator, std::allocator<char16_t>>::value);
static_assert(!CanDeduce<wchar_t const*, NotAnAllocator<wchar_t>>::value);
TEST_CONSTEXPR_CXX20 bool test() {
{
const char* s = "12345678901234";
std::basic_string s1(s, s+10); // Can't use {} here
using S = decltype(s1); // what type did we get?
static_assert(std::is_same_v<S::value_type, char>, "");
static_assert(std::is_same_v<S::traits_type, std::char_traits<char>>, "");
static_assert(std::is_same_v<S::allocator_type, std::allocator<char>>, "");
assert(s1.size() == 10);
assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
}
{
const char* s = "12345678901234";
std::basic_string s1{s, s+10, std::allocator<char>{}};
using S = decltype(s1); // what type did we get?
static_assert(std::is_same_v<S::value_type, char>, "");
static_assert(std::is_same_v<S::traits_type, std::char_traits<char>>, "");
static_assert(std::is_same_v<S::allocator_type, std::allocator<char>>, "");
assert(s1.size() == 10);
assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
}
{
const wchar_t* s = L"12345678901234";
std::basic_string s1{s, s+10, test_allocator<wchar_t>{}};
using S = decltype(s1); // what type did we get?
static_assert(std::is_same_v<S::value_type, wchar_t>, "");
static_assert(std::is_same_v<S::traits_type, std::char_traits<wchar_t>>, "");
static_assert(std::is_same_v<S::allocator_type, test_allocator<wchar_t>>, "");
assert(s1.size() == 10);
assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
}
{
const char16_t* s = u"12345678901234";
std::basic_string s1{s, s+10, min_allocator<char16_t>{}};
using S = decltype(s1); // what type did we get?
static_assert(std::is_same_v<S::value_type, char16_t>, "");
static_assert(std::is_same_v<S::traits_type, std::char_traits<char16_t>>, "");
static_assert(std::is_same_v<S::allocator_type, min_allocator<char16_t>>, "");
assert(s1.size() == 10);
assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
}
{
const char32_t* s = U"12345678901234";
std::basic_string s1{s, s+10, explicit_allocator<char32_t>{}};
using S = decltype(s1); // what type did we get?
static_assert(std::is_same_v<S::value_type, char32_t>, "");
static_assert(std::is_same_v<S::traits_type, std::char_traits<char32_t>>, "");
static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
assert(s1.size() == 10);
assert(s1.compare(0, s1.size(), s, s1.size()) == 0);
}
return true;
}
int main(int, char**)
{
test();
#if TEST_STD_VER > 17
static_assert(test());
#endif
return 0;
}
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