source: vbox/trunk/include/iprt/nocrt/memory

/** @file
 * IPRT / No-CRT - Minimal C++ std::memory.
 */

/*
 * Copyright (C) 2022-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, in version 3 of the
 * License.
 *
 * 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 GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 */

#ifndef VBOX_INCLUDED_SRC_nocrt_memory
#define VBOX_INCLUDED_SRC_nocrt_memory
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif

#include <iprt/nocrt/cstddef>
#include <iprt/nocrt/new>

namespace std
{
    /**
     * Simple allocator - not C++11 compliant.
     */
    template<class a_Type> class allocator
    {
    public:
        typedef a_Type              value_type;
        typedef a_Type const       &const_reference;
        typedef a_Type             *pointer;
        typedef a_Type const       *const_pointer;
        typedef std::size_t         size_type;
        typedef std::ptrdiff_t      difference_type;

    public:
        allocator() RT_NOEXCEPT
        { }

        allocator(allocator const &a_rThat) RT_NOEXCEPT
        { RT_NOREF(a_rThat); }

        ~allocator()
        { }

        a_Type *allocate(size_type a_cItems, const void *a_pvHint = NULL)
        {
            RT_NOREF(a_pvHint);
            Assert(a_cItems <= max_size()); /** @todo throw stuff */
            return static_cast<pointer>(::operator new(sizeof(value_type) * a_cItems));
        }

        void deallocate(a_Type *a_paItems, size_type a_cItems)
        {
            if (a_paItems && a_cItems > 0)
                ::operator delete(a_paItems);
        }

        size_type max_size() const
        {
            /* whatever */
#if ARCH_BITS >= 64
            return _4G / sizeof(value_type);
#else
            return _512M / sizeof(value_type);
#endif
        }

        void construct(pointer a_pDst, const_reference a_rSrc)
        {
            ::new (static_cast<void *>(a_pDst)) a_Type(a_rSrc);
        }

        void destroy(pointer a_pDst)
        {
            a_pDst->~value_type();
        }
    };

    /** @todo make_unique and unique   */
}

#endif /* !VBOX_INCLUDED_SRC_nocrt_memory */