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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
//
//===----------------------------------------------------------------------===//
// REQUIRES: std-at-least-c++23
// <ranges>
// friend constexpr bool operator==(const iterator& x, const iterator& y)
// requires ref-is-glvalue && forward_range<Base> &&
// equality_comparable<InnerIter>;
#include <ranges>
#include <array>
#include <cassert>
#include <utility>
#include "../types.h"
#include "test_comparisons.h"
template <class I1, class I2 = I1>
concept CanEq = requires(const I1& i1, const I2& i2) {
{ i1 == i2 } -> std::same_as<bool>;
{ i2 == i1 } -> std::same_as<bool>;
{ i1 != i2 } -> std::same_as<bool>;
{ i2 != i1 } -> std::same_as<bool>;
};
constexpr bool test() {
{ // `V` and `Pattern` are not empty. Test return types too.
using V = std::array<std::array<int, 2>, 3>;
using Pattern = std::array<long, 1>;
using JWV = std::ranges::join_with_view<std::ranges::owning_view<V>, std::ranges::owning_view<Pattern>>;
using Iter = std::ranges::iterator_t<JWV>;
using CIter = std::ranges::iterator_t<const JWV>;
static_assert(!std::same_as<Iter, CIter>);
static_assert(CanEq<Iter>);
static_assert(CanEq<CIter>);
static_assert(CanEq<Iter, CIter>);
JWV jwv(V{{{9, 8}, {7, 6}, {5, 4}}}, Pattern{0L});
Iter it1 = jwv.begin();
assert(*it1 == 9);
assert(testEquality(it1, it1, true));
Iter it2 = std::ranges::prev(jwv.end());
assert(*it2 == 4);
assert(testEquality(it2, it2, true));
assert(testEquality(it1, it2, false));
CIter cit1 = std::as_const(jwv).begin();
assert(*cit1 == 9);
assert(testEquality(cit1, cit1, true));
assert(testEquality(it1, cit1, true));
assert(testEquality(it2, cit1, false));
CIter cit2 = std::ranges::prev(std::as_const(jwv).end());
assert(*cit2 == 4);
assert(testEquality(cit2, cit2, true));
assert(testEquality(cit1, cit2, false));
assert(testEquality(it1, cit2, false));
assert(testEquality(it2, cit2, true));
// `it1.inner_it_` and `it2.inner_it_` are equal, but `it1.outer_it_` and `it2.outer_it_` are not.
std::ranges::advance(it1, 2);
assert(*it1 == 0);
std::ranges::advance(it2, -2);
assert(*it2 == 0);
assert(testEquality(it1, it2, false));
// `cit1.inner_it_` and `cit2.inner_it_` are equal, but `cit1.outer_it_` and `cit2.outer_it_` are not.
std::ranges::advance(cit1, 2);
assert(*cit1 == 0);
assert(testEquality(it1, cit1, true));
std::ranges::advance(cit2, -2);
assert(*cit2 == 0);
assert(testEquality(it2, cit2, true));
assert(testEquality(cit1, cit2, false));
// `it1.inner_it_` and `it2.inner_it_` are equal, `it1.outer_it_` and `it2.outer_it_` are equal too.
// `it1.inner_it_index()` and `it2.inner_it_index()` are equal to 1.
++it1;
assert(*it1 == 7);
std::ranges::advance(it2, -2);
assert(*it2 == 7);
assert(testEquality(it1, it2, true));
// `cit1.inner_it_` and `cit2.inner_it_` are equal, `cit1.outer_it_` and `cit2.outer_it_` are equal too.
// `cit1.inner_it_index()` and `cit2.inner_it_index()` are equal to 1.
++cit1;
assert(*cit1 == 7);
assert(testEquality(it1, cit1, true));
std::ranges::advance(cit2, -2);
assert(*cit2 == 7);
assert(testEquality(it2, cit2, true));
assert(testEquality(cit1, cit2, true));
// `it1.inner_it_` and `it2.inner_it_` are equal, `it1.outer_it_` and `it2.outer_it_` are equal too.
// `it1.inner_it_index()` and `it2.inner_it_index()` are equal to 0.
--it1;
assert(*it1 == 0);
--it2;
assert(*it2 == 0);
assert(testEquality(it1, it2, true));
// `cit1.inner_it_` and `cit2.inner_it_` are equal, `cit1.outer_it_` and `cit2.outer_it_` are equal too.
// `cit1.inner_it_index()` and `cit2.inner_it_index()` are equal to 0.
--cit1;
assert(*cit1 == 0);
assert(testEquality(it1, cit1, true));
--cit2;
assert(*cit2 == 0);
assert(testEquality(it2, cit2, true));
assert(testEquality(cit2, cit2, true));
}
{ // `InnerIter` models input iterator and equality comparable. `Pattern` is empty.
using Inner = BasicVectorView<int, ViewProperties{.common = false}, EqComparableInputIter>;
using V = std::vector<Inner>;
using Pattern = std::ranges::empty_view<int>;
using JWV = std::ranges::join_with_view<std::ranges::owning_view<V>, std::ranges::owning_view<Pattern>>;
using Iter = std::ranges::iterator_t<JWV>;
using CIter = std::ranges::iterator_t<const JWV>;
static_assert(!std::same_as<Iter, CIter>);
static_assert(CanEq<Iter>);
static_assert(CanEq<CIter>);
static_assert(!CanEq<CIter, Iter>);
JWV jwv(V{Inner{1, 2}, Inner{5, 6}, Inner{9, 0}}, Pattern{});
{
Iter it1 = jwv.begin();
assert(*it1 == 1);
Iter it2 = std::ranges::next(jwv.begin(), 2);
assert(*it2 == 5);
assert(testEquality(it1, it2, false));
++it1;
++it1;
assert(testEquality(it1, it2, true));
++it1;
assert(testEquality(it1, it2, false));
}
{
CIter cit1 = std::as_const(jwv).begin();
assert(*cit1 == 1);
CIter cit2 = std::ranges::next(std::as_const(jwv).begin(), 2);
assert(*cit2 == 5);
assert(testEquality(cit1, cit2, false));
++cit1;
++cit1;
assert(testEquality(cit1, cit2, true));
++cit1;
assert(testEquality(cit1, cit2, false));
}
}
{ // `Pattern` is not empty. Some elements of `V` are.
using Inner = BasicVectorView<int, ViewProperties{.common = false}, EqComparableInputIter>;
using V = BasicVectorView<Inner, ViewProperties{}, forward_iterator>;
using Pattern = BasicVectorView<int, ViewProperties{.common = false}, forward_iterator>;
using JWV = std::ranges::join_with_view<V, Pattern>;
using Iter = std::ranges::iterator_t<JWV>;
using CIter = std::ranges::iterator_t<const JWV>;
static_assert(!std::same_as<Iter, CIter>);
static_assert(CanEq<Iter>);
static_assert(CanEq<CIter>);
static_assert(!CanEq<CIter, Iter>);
JWV jwv(V{Inner{1}, Inner{}, Inner{27}}, Pattern{0});
{
Iter it1 = jwv.begin();
assert(*it1 == 1);
++it1;
assert(*it1 == 0);
Iter it2 = jwv.begin();
assert(testEquality(it1, it2, false));
++it2;
assert(testEquality(it1, it2, true));
++it2;
assert(*it1 == *it2);
assert(testEquality(it1, it2, false));
std::ranges::advance(it1, 2);
++it2;
assert(*it1 == *it2);
assert(testEquality(it1, it2, true));
}
{
CIter cit1 = std::as_const(jwv).begin();
assert(*cit1 == 1);
++cit1;
assert(*cit1 == 0);
CIter cit2 = std::as_const(jwv).begin();
assert(testEquality(cit1, cit2, false));
++cit2;
assert(testEquality(cit1, cit2, true));
++cit2;
assert(*cit1 == *cit2);
assert(testEquality(cit1, cit2, false));
std::ranges::advance(cit1, 2);
++cit2;
assert(*cit1 == *cit2);
assert(testEquality(cit1, cit2, true));
}
}
{ // `ref-is-glvalue` is false
using Inner = std::vector<int>;
using V = RvalueVector<Inner>;
using Pattern = std::ranges::empty_view<int>;
using JWV = std::ranges::join_with_view<std::ranges::owning_view<V>, std::ranges::owning_view<Pattern>>;
using Iter = std::ranges::iterator_t<JWV>;
static_assert(!CanEq<Iter>);
}
{ // `Base` does not model forward range
using Inner = std::vector<int>;
using V = BasicVectorView<Inner, ViewProperties{}, DefaultCtorInputIter>;
using Pattern = std::ranges::empty_view<int>;
using JWV = std::ranges::join_with_view<std::ranges::owning_view<V>, std::ranges::owning_view<Pattern>>;
using Iter = std::ranges::iterator_t<JWV>;
static_assert(!CanEq<Iter>);
}
{ // `InnerIter` does not model equality comparable
using Inner = BasicVectorView<int, ViewProperties{.common = false}, cpp20_input_iterator>;
using V = std::vector<Inner>;
using Pattern = std::ranges::empty_view<int>;
using JWV = std::ranges::join_with_view<std::ranges::owning_view<V>, std::ranges::owning_view<Pattern>>;
using Iter = std::ranges::iterator_t<JWV>;
using CIter = std::ranges::iterator_t<const JWV>;
static_assert(!CanEq<Iter>);
static_assert(!CanEq<CIter>);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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