llvm/libcxx/test/std/thread/futures/futures.promise/alloc_ctor.pass.cpp

//===----------------------------------------------------------------------===//
//
// 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: no-threads
// UNSUPPORTED: c++03

// <future>

// class promise<R>

// template <class Allocator>
//   promise(allocator_arg_t, const Allocator& a);

#include <future>
#include <cassert>

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

int main(int, char**)
{
    test_allocator_statistics alloc_stats;
    assert(alloc_stats.alloc_count == 0);
    {
        std::promise<int> p(std::allocator_arg, test_allocator<int>(42, &alloc_stats));
        assert(alloc_stats.alloc_count == 1);
        std::future<int> f = p.get_future();
        assert(alloc_stats.alloc_count == 1);
        assert(f.valid());
    }
    assert(alloc_stats.alloc_count == 0);
    {
        std::promise<int&> p(std::allocator_arg, test_allocator<int>(42, &alloc_stats));
        assert(alloc_stats.alloc_count == 1);
        std::future<int&> f = p.get_future();
        assert(alloc_stats.alloc_count == 1);
        assert(f.valid());
    }
    assert(alloc_stats.alloc_count == 0);
    {
        std::promise<void> p(std::allocator_arg, test_allocator<void>(42, &alloc_stats));
        assert(alloc_stats.alloc_count == 1);
        std::future<void> f = p.get_future();
        assert(alloc_stats.alloc_count == 1);
        assert(f.valid());
    }
    assert(alloc_stats.alloc_count == 0);
    // Test with a minimal allocator
    {
        std::promise<int> p(std::allocator_arg, bare_allocator<void>());
        std::future<int> f = p.get_future();
        assert(f.valid());
    }
    {
        std::promise<int&> p(std::allocator_arg, bare_allocator<void>());
        std::future<int&> f = p.get_future();
        assert(f.valid());
    }
    {
        std::promise<void> p(std::allocator_arg, bare_allocator<void>());
        std::future<void> f = p.get_future();
        assert(f.valid());
    }
    // Test with a minimal allocator that returns class-type pointers
    {
        std::promise<int> p(std::allocator_arg, min_allocator<void>());
        std::future<int> f = p.get_future();
        assert(f.valid());
    }
    {
        std::promise<int&> p(std::allocator_arg, min_allocator<void>());
        std::future<int&> f = p.get_future();
        assert(f.valid());
    }
    {
        std::promise<void> p(std::allocator_arg, min_allocator<void>());
        std::future<void> f = p.get_future();
        assert(f.valid());
    }

  return 0;
}