ValueContainer.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
// This software owned by Onix Solutions Limited [OnixS] and is
// protected by copyright law and international copyright treaties.
//
// Access to and use of the software is governed by the terms of the applicable
// OnixS Software Services Agreement (the Agreement) and Customer end user license
// agreements granting a non-assignable, non-transferable and non-exclusive license
// to use the software for it's own data processing purposes under the terms defined
// in the Agreement.
//
// Except as otherwise granted within the terms of the Agreement, copying or
// reproduction of any part of this source code or associated reference material
// to any other location for further reproduction or redistribution, and any
// amendments to this copyright notice, are expressly prohibited.
//
// Any reproduction or redistribution for sale or hiring of the Software not in
// accordance with the terms of the Agreement is a violation of copyright law.
//
 
#pragma once
 
#include <OnixS/CME/iLink3/ABI.h>
#include <OnixS/CME/iLink3/messaging/Memory.h>
 
#include <new>
 
ONIXS_ILINK3_MESSAGING_TAGBASED_NAMESPACE_BEGIN

ONIXS_ILINK3_LTWT_CLASS
ValueContainer
{
    enum
    {
        Capacity = 16
    };
 
    Byte bytes_[Capacity];

    void* place() ONIXS_ILINK3_NOTHROW
    {
        return static_cast<void*>(bytes_);
    }

    const void* place() const ONIXS_ILINK3_NOTHROW
    {
        return static_cast<const void*>(bytes_);
    }
 
public:
    ValueContainer() ONIXS_ILINK3_DEFAULT;

    template <typename Value>
    ONIXS_ILINK3_NODISCARD Value& get() ONIXS_ILINK3_NOTHROW
    {
        ONIXS_ILINK3_STATIC_ASSERT_MSG
        (
            (sizeof(Value) <= static_cast<size_t>(Capacity)), "Capacity is not sufficient for storing values of the given type."
        );
 
        return * static_cast<Value*> (place());
    }

    template <typename Value>
    ONIXS_ILINK3_NODISCARD const Value& get() const ONIXS_ILINK3_NOTHROW
    {
        ONIXS_ILINK3_STATIC_ASSERT_MSG
        (
            (sizeof(Value) <= static_cast<size_t>(Capacity)), "Capacity of the storage is not sufficient to store values of the specified type."
        );
 
        return * static_cast<const Value*>(place());
    }

    template<class Value>
    ValueContainer& assign(const Value& value) ONIXS_ILINK3_NOTHROW
    {
        ONIXS_ILINK3_STATIC_ASSERT_MSG
        (
            (sizeof(Value) <= static_cast<size_t>(Capacity)), "Capacity of the storage is not sufficient to store values of the specified type."
        );
 
#if defined (ONIXS_ILINK3_CXX11)
        static_assert(
            std::is_nothrow_copy_constructible<Value>::value,
            "must be noexcept");
#endif
 
        new (place()) Value(value);
 
        return *this;
    }
};
 
ONIXS_ILINK3_MESSAGING_TAGBASED_NAMESPACE_END