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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
// UNSUPPORTED: libcpp-no-concepts
// UNSUPPORTED: gcc-10
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// template<range R>
// requires is_object_v<R>
// class ref_view;
#include <ranges>
#include <cassert>
#include "test_macros.h"
#include "test_iterators.h"
int globalBuff[8];
template<class T>
concept ValidRefView = requires { typename std::ranges::ref_view<T>; };
struct Range {
int start = 0;
friend constexpr int* begin(Range const& range) { return globalBuff + range.start; }
friend constexpr int* end(Range const&) { return globalBuff + 8; }
friend constexpr int* begin(Range& range) { return globalBuff + range.start; }
friend constexpr int* end(Range&) { return globalBuff + 8; }
};
struct BeginOnly {
friend int* begin(BeginOnly const&);
friend int* begin(BeginOnly &);
};
static_assert( ValidRefView<Range>);
static_assert(!ValidRefView<BeginOnly>);
static_assert(!ValidRefView<int (&)[4]>);
static_assert( ValidRefView<int[4]>);
static_assert(std::derived_from<std::ranges::ref_view<Range>, std::ranges::view_interface<std::ranges::ref_view<Range>>>);
struct RangeConvertible {
operator Range& ();
};
struct RValueRangeConvertible {
operator Range&& ();
};
static_assert( std::is_constructible_v<std::ranges::ref_view<Range>, Range&>);
static_assert( std::is_constructible_v<std::ranges::ref_view<Range>, RangeConvertible>);
static_assert(!std::is_constructible_v<std::ranges::ref_view<Range>, RValueRangeConvertible>);
struct ConstConvertibleToLValueAndRValue {
operator Range& () const;
operator Range&& () const;
};
static_assert( std::is_convertible_v<RangeConvertible, std::ranges::ref_view<Range>>);
static_assert(!std::is_convertible_v<RValueRangeConvertible, std::ranges::ref_view<Range>>);
static_assert(!std::is_convertible_v<ConstConvertibleToLValueAndRValue, std::ranges::ref_view<Range>>);
struct ForwardRange {
constexpr forward_iterator<int*> begin() const { return forward_iterator<int*>(globalBuff); }
constexpr forward_iterator<int*> end() const { return forward_iterator<int*>(globalBuff + 8); }
};
struct Cpp17InputRange {
struct sentinel {
friend constexpr bool operator==(sentinel, cpp17_input_iterator<int*> iter) { return iter.base() == globalBuff + 8; }
friend constexpr std::ptrdiff_t operator-(sentinel, cpp17_input_iterator<int*>) { return -8; }
friend constexpr std::ptrdiff_t operator-(cpp17_input_iterator<int*>, sentinel) { return 8; }
};
constexpr cpp17_input_iterator<int*> begin() const {
return cpp17_input_iterator<int*>(globalBuff);
}
constexpr sentinel end() const { return {}; }
};
struct Cpp20InputRange {
struct sentinel {
friend constexpr bool operator==(sentinel, const cpp20_input_iterator<int*> &iter) { return iter.base() == globalBuff + 8; }
friend constexpr std::ptrdiff_t operator-(sentinel, const cpp20_input_iterator<int*>&) { return -8; }
};
constexpr cpp20_input_iterator<int*> begin() const {
return cpp20_input_iterator<int*>(globalBuff);
}
constexpr sentinel end() const { return {}; }
};
template<>
inline constexpr bool std::ranges::enable_borrowed_range<Cpp20InputRange> = true;
template<class R>
concept EmptyIsInvocable = requires (std::ranges::ref_view<R> view) { view.empty(); };
template<class R>
concept SizeIsInvocable = requires (std::ranges::ref_view<R> view) { view.size(); };
template<class R>
concept DataIsInvocable = requires (std::ranges::ref_view<R> view) { view.data(); };
// Testing ctad.
static_assert(std::same_as<decltype(std::ranges::ref_view(std::declval<Range&>())),
std::ranges::ref_view<Range>>);
constexpr bool test() {
{
// ref_view::base
Range range;
std::ranges::ref_view<Range> view{range};
assert(view.begin() == globalBuff);
view.base() = Range{2};
assert(view.begin() == globalBuff + 2);
}
{
// ref_view::begin
Range range1;
std::ranges::ref_view<Range> view1 = range1;
assert(view1.begin() == globalBuff);
ForwardRange range2;
std::ranges::ref_view<ForwardRange> view2 = range2;
assert(view2.begin().base() == globalBuff);
Cpp17InputRange range3;
std::ranges::ref_view<Cpp17InputRange> view3 = range3;
assert(view3.begin().base() == globalBuff);
Cpp20InputRange range4;
std::ranges::ref_view<Cpp20InputRange> view4 = range4;
assert(view4.begin().base() == globalBuff);
}
{
// ref_view::end
Range range1;
std::ranges::ref_view<Range> view1 = range1;
assert(view1.end() == globalBuff + 8);
ForwardRange range2;
std::ranges::ref_view<ForwardRange> view2 = range2;
assert(view2.end().base() == globalBuff + 8);
Cpp17InputRange range3;
std::ranges::ref_view<Cpp17InputRange> view3 = range3;
assert(view3.end() == cpp17_input_iterator(globalBuff + 8));
Cpp20InputRange range4;
std::ranges::ref_view<Cpp20InputRange> view4 = range4;
assert(view4.end() == cpp20_input_iterator(globalBuff + 8));
}
{
// ref_view::empty
Range range{8};
std::ranges::ref_view<Range> view1 = range;
assert(view1.empty());
ForwardRange range2;
std::ranges::ref_view<ForwardRange> view2 = range2;
assert(!view2.empty());
static_assert(!EmptyIsInvocable<Cpp17InputRange>);
static_assert(!EmptyIsInvocable<Cpp20InputRange>);
}
{
// ref_view::size
Range range1{8};
std::ranges::ref_view<Range> view1 = range1;
assert(view1.size() == 0);
Range range2{2};
std::ranges::ref_view<Range> view2 = range2;
assert(view2.size() == 6);
static_assert(!SizeIsInvocable<ForwardRange>);
}
{
// ref_view::data
Range range1;
std::ranges::ref_view<Range> view1 = range1;
assert(view1.data() == globalBuff);
Range range2{2};
std::ranges::ref_view<Range> view2 = range2;
assert(view2.data() == globalBuff + 2);
static_assert(!DataIsInvocable<ForwardRange>);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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