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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
// <flat_set>
// size_type erase(K&& k);
#include <compare>
#include <concepts>
#include <deque>
#include <flat_set>
#include <functional>
#include <string>
#include <utility>
#include <vector>
#include "MinSequenceContainer.h"
#include "../helpers.h"
#include "test_macros.h"
#include "min_allocator.h"
// Constraints: The qualified-id Compare::is_transparent is valid and denotes a type.
template <class M>
concept CanErase = requires(M m, Transparent<int> k) { m.erase(k); };
using TransparentSet = std::flat_set<int, TransparentComparator>;
using NonTransparentSet = std::flat_set<int, NonTransparentComparator>;
static_assert(CanErase<TransparentSet>);
static_assert(!CanErase<const TransparentSet>);
static_assert(!CanErase<NonTransparentSet>);
static_assert(!CanErase<const NonTransparentSet>);
template <class Key, class It>
struct HeterogeneousKey {
constexpr explicit HeterogeneousKey(Key key, It it) : key_(key), it_(it) {}
constexpr operator It() && { return it_; }
constexpr auto operator<=>(Key key) const { return key_ <=> key; }
constexpr friend bool operator<(const HeterogeneousKey&, const HeterogeneousKey&) {
assert(false);
return false;
}
Key key_;
It it_;
};
template <class KeyContainer>
constexpr void test_one() {
using Key = typename KeyContainer::value_type;
using M = std::flat_set<Key, std::less<Key>, KeyContainer>;
M m = {1, 2, 3, 4};
ASSERT_SAME_TYPE(decltype(m.erase(9)), typename M::size_type);
auto n = m.erase(3); // erase(K&&) [with K=int]
assert(n == 1);
assert((m == M{1, 2, 4}));
typename M::key_type lvalue = 2;
n = m.erase(lvalue); // erase(K&&) [with K=int&]
assert(n == 1);
assert((m == M{1, 4}));
const typename M::key_type const_lvalue = 1;
n = m.erase(const_lvalue); // erase(const key_type&)
assert(n == 1);
assert((m == M{4}));
}
template <class KeyContainer>
constexpr void test_transparent_comparator() {
using M = std::flat_set<std::string, TransparentComparator, KeyContainer>;
{
M m = {"alpha", "beta", "epsilon", "eta", "gamma"};
ASSERT_SAME_TYPE(decltype(m.erase(Transparent<std::string>{"abc"})), typename M::size_type);
auto n = m.erase(Transparent<std::string>{"epsilon"});
assert(n == 1);
M expected = {"alpha", "beta", "eta", "gamma"};
assert(m == expected);
auto n2 = m.erase(Transparent<std::string>{"aaa"});
assert(n2 == 0);
assert(m == expected);
}
{
// was empty
M m;
auto n = m.erase(Transparent<std::string>{"epsilon"});
assert(n == 0);
assert(m.empty());
}
}
constexpr bool test() {
test_one<std::vector<int>>();
#ifndef __cpp_lib_constexpr_deque
if (!TEST_IS_CONSTANT_EVALUATED)
#endif
test_one<std::deque<int>>();
test_one<MinSequenceContainer<int>>();
test_one<std::vector<int, min_allocator<int>>>();
test_transparent_comparator<std::vector<std::string>>();
#ifndef __cpp_lib_constexpr_deque
if (!TEST_IS_CONSTANT_EVALUATED)
#endif
test_transparent_comparator<std::deque<std::string>>();
test_transparent_comparator<MinSequenceContainer<std::string>>();
test_transparent_comparator<std::vector<std::string, min_allocator<std::string>>>();
{
// P2077's HeterogeneousKey example
using M = std::flat_set<int, std::less<>>;
M m = {1, 2, 3, 4, 5, 6, 7, 8};
auto h1 = HeterogeneousKey<int, M::iterator>(8, m.begin());
std::same_as<M::size_type> auto n = m.erase(h1); // lvalue is not convertible to It; erase(K&&) is the best match
assert(n == 1);
assert((m == M{1, 2, 3, 4, 5, 6, 7}));
std::same_as<M::iterator> auto it = m.erase(std::move(h1)); // rvalue is convertible to It; erase(K&&) drops out
assert(it == m.begin());
assert((m == M{2, 3, 4, 5, 6, 7}));
}
{
using M = std::flat_set<int, std::less<>>;
M m = {1, 2, 3, 4, 5, 6, 7, 8};
auto h1 = HeterogeneousKey<int, M::const_iterator>(8, m.begin());
std::same_as<M::size_type> auto n = m.erase(h1); // lvalue is not convertible to It; erase(K&&) is the best match
assert(n == 1);
assert((m == M{1, 2, 3, 4, 5, 6, 7}));
std::same_as<M::iterator> auto it = m.erase(std::move(h1)); // rvalue is convertible to It; erase(K&&) drops out
assert(it == m.begin());
assert((m == M{2, 3, 4, 5, 6, 7}));
}
{
bool transparent_used = false;
TransparentComparator c(transparent_used);
std::flat_set<int, TransparentComparator> m(std::sorted_unique, {1, 2, 3}, c);
assert(!transparent_used);
auto n = m.erase(Transparent<int>{3});
assert(n == 1);
assert(transparent_used);
}
{
// LWG4239 std::string and C string literal
using M = std::flat_set<std::string, std::less<>>;
M m{"alpha", "beta", "epsilon", "eta", "gamma"};
auto n = m.erase("beta");
assert(n == 1);
}
return true;
}
void test_exception() {
auto erase_transparent = [](auto& m, auto key_arg) {
using Set = std::decay_t<decltype(m)>;
using Key = typename Set::key_type;
m.erase(Transparent<Key>{key_arg});
};
test_erase_exception_guarantee(erase_transparent);
}
int main(int, char**) {
test();
test_exception();
#if TEST_STD_VER >= 26
static_assert(test());
#endif
return 0;
}
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