test/std/thread/futures/futures.promise/dtor.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: libcpp-has-no-threads
// UNSUPPORTED: c++03

// <future>

// class promise<R>

// ~promise();

#include <future>
#include <cassert>

#include "test_macros.h"

int main(int, char**)
{
    {
        typedef int T;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
            p.set_value(3);
        }
        assert(f.get() == 3);
    }
#ifndef TEST_HAS_NO_EXCEPTIONS
    {
        typedef int T;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
        }
        try
        {
            T i = f.get();
            ((void)i); // Prevent unused warning
            assert(false);
        }
        catch (const std::future_error& e)
        {
            assert(e.code() == make_error_code(std::future_errc::broken_promise));
        }
    }
#endif

    {
        typedef int& T;
        int i = 4;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
            p.set_value(i);
        }
        assert(&f.get() == &i);
    }
#ifndef TEST_HAS_NO_EXCEPTIONS
    {
        typedef int& T;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
        }
        try
        {
            T i = f.get();
            ((void)i); // Prevent unused warning
            assert(false);
        }
        catch (const std::future_error& e)
        {
            assert(e.code() == make_error_code(std::future_errc::broken_promise));
        }
    }
#endif

    {
        typedef void T;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
            p.set_value();
        }
        f.get();
        assert(true);
    }
#ifndef TEST_HAS_NO_EXCEPTIONS
    {
        typedef void T;
        std::future<T> f;
        {
            std::promise<T> p;
            f = p.get_future();
        }
        try
        {
            f.get();
            assert(false);
        }
        catch (const std::future_error& e)
        {
            // LWG 2056 changed the values of future_errc, so if we're using new
            // headers with an old library the error codes won't line up.
            //
            // Note that this particular check only applies to promise<void>
            // since the other specializations happen to be implemented in the
            // header rather than the library.
            assert(
                e.code() == make_error_code(std::future_errc::broken_promise) ||
                e.code() == std::error_code(0, std::future_category()));
        }
    }
#endif

  return 0;
}