/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */
#pragma once

#include "mongo/base/concept/convertible_to.h"

namespace mongo {
namespace concept {
    /**
     * The `UniquePtr` Concept models a movable owning pointer of an object.
     * `std::unique_ptr< T >` is a model of `mongo::concept::UniquePtr< T >`.
     */
    template <typename T>
    struct UniquePtr {
        /** The `UniquePtr< T >` must retire its pointer to `T` on destruction. */
        ~UniquePtr() noexcept;

        UniquePtr(UniquePtr&& p);
        UniquePtr& operator=(UniquePtr&& p);

        UniquePtr();
        UniquePtr(T* p);

        ConvertibleTo<T*> operator->() const;
        T& operator*() const;

        explicit operator bool() const;

        ConvertibleTo<T*> get() const;

        void reset() noexcept;
        void reset(ConvertibleTo<T*>);
    };

    /*! A `UniquePtr` object must be equality comparable. */
    template <typename T>
    bool operator==(const UniquePtr<T>& lhs, const UniquePtr<T>& rhs);

    /*! A `UniquePtr` object must be inequality comparable. */
    template <typename T>
    bool operator!=(const UniquePtr<T>& lhs, const UniquePtr<T>& rhs);
}  // namespace concept
}  // namespace mongo