//===----------------------------------------------------------------------===//
//
// 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++98, c++03, c++11, c++14, c++17

// <unordered_set>

// template <class T, class Hash, class Compare, class Allocator, class Predicate>
//   void erase_if(unorderd_set<T, Hash, Compare, Allocator>& c, Predicate pred);

#include <unordered_set>

#include "test_macros.h"
#include "test_allocator.h"
#include "min_allocator.h"

using Init = std::initializer_list<int>;

template <typename M>
M make (Init vals)
{
    M ret;
    for (int v : vals)
        ret.insert(v);
    return ret;
}

template <typename M, typename Pred>
void
test0(Init vals, Pred p, Init expected)
{
    M s = make<M> (vals);
    ASSERT_SAME_TYPE(void, decltype(std::erase_if(s, p)));
    std::erase_if(s, p);
    M e = make<M>(expected);
    assert((std::is_permutation(s.begin(), s.end(), e.begin(), e.end())));
}


template <typename S>
void test()
{
    auto is1 = [](auto v) { return v == 1;};
    auto is2 = [](auto v) { return v == 2;};
    auto is3 = [](auto v) { return v == 3;};
    auto is4 = [](auto v) { return v == 4;};
    auto True  = [](auto) { return true; };
    auto False = [](auto) { return false; };
    
    test0<S>({}, is1, {});

    test0<S>({1}, is1, {});
    test0<S>({1}, is2, {1});

    test0<S>({1,2}, is1, {2});
    test0<S>({1,2}, is2, {1});
    test0<S>({1,2}, is3, {1,2});

    test0<S>({1,2,3}, is1, {2,3});
    test0<S>({1,2,3}, is2, {1,3});
    test0<S>({1,2,3}, is3, {1,2});
    test0<S>({1,2,3}, is4, {1,2,3});

    test0<S>({1,2,3}, True,  {});
    test0<S>({1,2,3}, False, {1,2,3});
}

int main(int, char**)
{
    test<std::unordered_set<int>>();
    test<std::unordered_set<int, std::hash<int>, std::equal_to<int>, min_allocator<int>>> ();
    test<std::unordered_set<int, std::hash<int>, std::equal_to<int>, test_allocator<int>>> ();

    test<std::unordered_set<long>>();
    test<std::unordered_set<double>>();

  return 0;
}