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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, c++17, c++20
// To silence a GCC warning-turned-error re. `BadAlloc::value_type`.
// ADDITIONAL_COMPILE_FLAGS: -Wno-unused-local-typedefs
// template<ranges::input_range R,
// class Allocator = allocator<ranges::range_value_t<R>>>
// basic_string(from_range_t, R&&, Allocator = Allocator())
// -> basic_string<ranges::range_value_t<R>, char_traits<ranges::range_value_t<R>>,
// Allocator>; // C++23
//
// The deduction guide shall not participate in overload resolution if Allocator
// is a type that does not qualify as an allocator (in addition to the `input_range` concept being satisfied by `R`).
#include <array>
#include <string>
#include "deduction_guides_sfinae_checks.h"
#include "test_allocator.h"
int main(int, char**) {
using Char = char16_t;
{
std::basic_string c(std::from_range, std::array<Char, 0>());
static_assert(std::is_same_v<decltype(c), std::basic_string<Char>>);
}
{
using Alloc = test_allocator<Char>;
std::basic_string c(std::from_range, std::array<Char, 0>(), Alloc());
static_assert(std::is_same_v<decltype(c), std::basic_string<Char, std::char_traits<Char>, Alloc>>);
}
// Note: defining `value_type` is a workaround because one of the deduction guides will end up instantiating
// `basic_string`, and that would fail with a hard error if the given allocator doesn't define `value_type`.
struct BadAlloc { using value_type = char; };
SequenceContainerDeductionGuidesSfinaeAway<std::basic_string, std::basic_string<char>, BadAlloc>();
return 0;
}
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