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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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// There is a bug in older versions of Clang that causes trouble with constraints in classes like
// `ContainerWithDirectCtr`.
// XFAIL: apple-clang-15
// template<template<class...> class C, input_range R, class... Args>
// constexpr auto to(R&& r, Args&&... args); // Since C++23
#include <ranges>
#include <algorithm>
#include <array>
#include <cassert>
#include "container.h"
template <class ElementType>
struct ContainerWithDirectCtr : Container<ElementType, CtrChoice::DirectCtr> {
using Container<ElementType, CtrChoice::DirectCtr>::Container;
};
template <std::ranges::input_range Range>
ContainerWithDirectCtr(Range&&) -> ContainerWithDirectCtr<std::ranges::range_value_t<Range>>;
template <std::ranges::input_range Range>
ContainerWithDirectCtr(Range&&, int, char) -> ContainerWithDirectCtr<std::ranges::range_value_t<Range>>;
template <class ElementType>
struct ContainerWithFromRangeT : Container<ElementType, CtrChoice::FromRangeT> {
using Container<ElementType, CtrChoice::FromRangeT>::Container;
};
template <std::ranges::input_range Range>
ContainerWithFromRangeT(std::from_range_t, Range&&) -> ContainerWithFromRangeT<std::ranges::range_value_t<Range>>;
template <std::ranges::input_range Range>
ContainerWithFromRangeT(std::from_range_t, Range&&, int, char) ->
ContainerWithFromRangeT<std::ranges::range_value_t<Range>>;
template <class ElementType>
struct ContainerWithBeginEndPair : Container<ElementType, CtrChoice::BeginEndPair> {
using Container<ElementType, CtrChoice::BeginEndPair>::Container;
};
template <class Iter>
ContainerWithBeginEndPair(Iter, Iter) -> ContainerWithBeginEndPair<std::iter_value_t<Iter>>;
template <class Iter>
ContainerWithBeginEndPair(Iter, Iter, int, char) -> ContainerWithBeginEndPair<std::iter_value_t<Iter>>;
constexpr bool test() {
std::array in = {1, 2, 3, 4, 5};
int arg1 = 42;
char arg2 = 'a';
{ // Case 1 -- can construct directly from the given range.
{
std::same_as<ContainerWithDirectCtr<int>> decltype(auto) result = std::ranges::to<ContainerWithDirectCtr>(in);
assert(result.ctr_choice == CtrChoice::DirectCtr);
assert(std::ranges::equal(result, in));
assert((in | std::ranges::to<ContainerWithDirectCtr>()) == result);
}
{ // Extra arguments.
std::same_as<ContainerWithDirectCtr<int>> decltype(auto) result =
std::ranges::to<ContainerWithDirectCtr>(in, arg1, arg2);
assert(result.ctr_choice == CtrChoice::DirectCtr);
assert(std::ranges::equal(result, in));
assert(result.extra_arg1 == arg1);
assert(result.extra_arg2 == arg2);
assert((in | std::ranges::to<ContainerWithDirectCtr>(arg1, arg2)) == result);
}
}
{ // Case 2 -- can construct from the given range using the `from_range_t` tagged constructor.
{
std::same_as<ContainerWithFromRangeT<int>> decltype(auto) result = std::ranges::to<ContainerWithFromRangeT>(in);
assert(result.ctr_choice == CtrChoice::FromRangeT);
assert(std::ranges::equal(result, in));
assert((in | std::ranges::to<ContainerWithFromRangeT>()) == result);
}
{ // Extra arguments.
std::same_as<ContainerWithFromRangeT<int>> decltype(auto) result =
std::ranges::to<ContainerWithFromRangeT>(in, arg1, arg2);
assert(result.ctr_choice == CtrChoice::FromRangeT);
assert(std::ranges::equal(result, in));
assert(result.extra_arg1 == arg1);
assert(result.extra_arg2 == arg2);
assert((in | std::ranges::to<ContainerWithFromRangeT>(arg1, arg2)) == result);
}
}
{ // Case 3 -- can construct from a begin-end iterator pair.
{
std::same_as<ContainerWithBeginEndPair<int>> decltype(auto) result =
std::ranges::to<ContainerWithBeginEndPair>(in);
assert(result.ctr_choice == CtrChoice::BeginEndPair);
assert(std::ranges::equal(result, in));
assert((in | std::ranges::to<ContainerWithBeginEndPair>()) == result);
}
{ // Extra arguments.
std::same_as<ContainerWithBeginEndPair<int>> decltype(auto) result =
std::ranges::to<ContainerWithBeginEndPair>(in, arg1, arg2);
assert(result.ctr_choice == CtrChoice::BeginEndPair);
assert(std::ranges::equal(result, in));
assert(result.extra_arg1 == arg1);
assert(result.extra_arg2 == arg2);
assert((in | std::ranges::to<ContainerWithBeginEndPair>(arg1, arg2)) == result);
}
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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