//===----------------------------------------------------------------------===//
//
// 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
// <algorithm>
// template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
// class Proj = identity>
// requires sortable<I, Comp, Proj>
// constexpr I
// ranges::pop_heap(I first, S last, Comp comp = {}, Proj proj = {}); // since C++20
//
// template<random_access_range R, class Comp = ranges::less, class Proj = identity>
// requires sortable<iterator_t<R>, Comp, Proj>
// constexpr borrowed_iterator_t<R>
// ranges::pop_heap(R&& r, Comp comp = {}, Proj proj = {}); // since C++20
#include <algorithm>
#include <array>
#include <concepts>
#include <functional>
#include <memory>
#include <ranges>
#include "almost_satisfies_types.h"
#include "test_iterators.h"
// SFINAE tests.
using BadComparator = ComparatorNotCopyable<int*>;
static_assert(!std::sortable<int*, BadComparator>);
template <class Iter, class Sent = sentinel_wrapper<Iter>, class Comp = std::ranges::less>
concept HasPopHeapIt = requires(Iter first, Sent last, Comp comp) { std::ranges::make_heap(first, last, comp); };
static_assert(HasPopHeapIt<int*>);
static_assert(!HasPopHeapIt<RandomAccessIteratorNotDerivedFrom>);
static_assert(!HasPopHeapIt<RandomAccessIteratorBadIndex>);
static_assert(!HasPopHeapIt<int*, SentinelForNotSemiregular>);
static_assert(!HasPopHeapIt<int*, SentinelForNotWeaklyEqualityComparableWith>);
static_assert(!HasPopHeapIt<int*, int*, BadComparator>);
static_assert(!HasPopHeapIt<const int*>); // Doesn't satisfy `sortable`.
template <class Range, class Comp = std::ranges::less>
concept HasPopHeapR = requires(Range range, Comp comp) { std::ranges::make_heap(range, comp); };
static_assert(HasPopHeapR<UncheckedRange<int*>>);
static_assert(!HasPopHeapR<RandomAccessRangeNotDerivedFrom>);
static_assert(!HasPopHeapR<RandomAccessRangeBadIndex>);
static_assert(!HasPopHeapR<UncheckedRange<int*, SentinelForNotSemiregular>>);
static_assert(!HasPopHeapR<UncheckedRange<int*, SentinelForNotWeaklyEqualityComparableWith>>);
static_assert(!HasPopHeapR<UncheckedRange<int*>, BadComparator>);
static_assert(!HasPopHeapR<UncheckedRange<const int*>>); // Doesn't satisfy `sortable`.
template <std::size_t N, class T, class Iter>
constexpr void verify_heap(const std::array<T, N>& heapified, Iter last, std::array<T, N> expected) {
assert(heapified == expected);
assert(std::to_address(base(last)) == heapified.data() + heapified.size());
assert(std::is_heap(heapified.begin(), heapified.end() - 1));
assert(*std::max_element(heapified.begin(), heapified.end()) == heapified.back());
}
template <class Iter, class Sent, std::size_t N>
constexpr void test_one(const std::array<int, N> input, std::array<int, N> expected) {
assert(!input.empty());
assert(std::is_heap(input.begin(), input.end()));
{ // (iterator, sentinel) overload.
auto heapified = input;
auto b = Iter(heapified.data());
auto e = Sent(Iter(heapified.data() + heapified.size()));
std::same_as<Iter> decltype(auto) last = std::ranges::pop_heap(b, e);
verify_heap(heapified, last, expected);
}
{ // (range) overload.
auto heapified = input;
auto b = Iter(heapified.data());
auto e = Sent(Iter(heapified.data() + heapified.size()));
auto range = std::ranges::subrange(b, e);
std::same_as<Iter> decltype(auto) last = std::ranges::pop_heap(range);
verify_heap(heapified, last, expected);
}
}
template <class Iter, class Sent>
constexpr void test_iterators_2() {
// 1-element sequence.
test_one<Iter, Sent, 1>({1}, {1});
// 2-element sequence.
test_one<Iter, Sent, 2>({2, 1}, {1, 2});
// 3-element sequence.
test_one<Iter, Sent, 3>({3, 1, 2}, {2, 1, 3});
// Longer sequence.
test_one<Iter, Sent, 8>({11, 8, 5, 6, 4, 3, 2, 1}, {8, 6, 5, 1, 4, 3, 2, 11});
// Longer sequence with duplicates.
test_one<Iter, Sent, 8>({8, 8, 6, 6, 1, 2, 2, 3}, {8, 6, 6, 3, 1, 2, 2, 8});
// All elements are the same.
test_one<Iter, Sent, 4>({1, 1, 1, 1}, {1, 1, 1, 1});
}
template <class Iter>
constexpr void test_iterators_1() {
test_iterators_2<Iter, Iter>();
test_iterators_2<Iter, sentinel_wrapper<Iter>>();
}
constexpr void test_iterators() {
test_iterators_1<random_access_iterator<int*>>();
test_iterators_1<contiguous_iterator<int*>>();
test_iterators_1<int*>();
}
constexpr bool test() {
test_iterators();
{ // A custom comparator works.
const std::array input = {1, 2, 3, 5, 4};
std::array expected = {2, 4, 3, 5, 1};
auto comp = std::ranges::greater{};
{
auto in = input;
auto last = std::ranges::pop_heap(in.begin(), in.end(), comp);
assert(in == expected);
assert(last == in.end());
assert(std::is_heap(in.begin(), in.end() - 1, comp));
}
{
auto in = input;
auto last = std::ranges::pop_heap(in, comp);
assert(in == expected);
assert(last == in.end());
assert(std::is_heap(in.begin(), in.end() - 1, comp));
}
}
{ // A custom projection works.
struct A {
int a;
constexpr auto operator<=>(const A&) const = default;
};
const std::array input = {A{3}, A{1}, A{2}};
std::array expected = {A{2}, A{1}, A{3}};
{
auto in = input;
auto last = std::ranges::pop_heap(in.begin(), in.end(), {}, &A::a);
verify_heap(in, last, expected);
}
{
auto in = input;
auto last = std::ranges::pop_heap(in, {}, &A::a);
verify_heap(in, last, expected);
}
}
{ // `std::invoke` is used in the implementation.
struct A {
int i;
constexpr A(int i_) : i(i_) {}
constexpr bool comparator(const A& rhs) const { return i < rhs.i; }
constexpr const A& projection() const { return *this; }
constexpr auto operator<=>(const A&) const = default;
};
const std::array input = {A{3}, A{1}, A{2}};
std::array expected = {A{2}, A{1}, A{3}};
{
auto in = input;
auto last = std::ranges::pop_heap(in.begin(), in.end(), &A::comparator, &A::projection);
verify_heap(in, last, expected);
}
{
auto in = input;
auto last = std::ranges::pop_heap(in, &A::comparator, &A::projection);
verify_heap(in, last, expected);
}
}
{ // `std::ranges::dangling` is returned.
[[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) result =
std::ranges::pop_heap(std::array{2, 1, 3});
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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