CopiedPtr.hpp

Go to the documentation of this file.

//
// Aurora C++ Library
// Copyright (c) 2012-2016 Jan Haller
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//


#ifndef AURORA_COPIEDPTR_HPP
#define AURORA_COPIEDPTR_HPP

#include <Aurora/SmartPtr/ClonersAndDeleters.hpp>
#include <Aurora/SmartPtr/Detail/PtrOwner.hpp>
#include <Aurora/Tools/SafeBool.hpp>
#include <Aurora/Tools/Swap.hpp>
#include <Aurora/Config.hpp>

#include <algorithm>
#include <type_traits>
#include <utility>


namespace aurora
{


template <typename T>
class CopiedPtr
{
    // ---------------------------------------------------------------------------------------------------------------------------
    // Public member functions
    public:
        CopiedPtr()
        : mOwner(nullptr)
        , mPointer(nullptr)
        {
        }

        CopiedPtr(std::nullptr_t)
        : mOwner(nullptr)
        , mPointer(nullptr)
        {
        }

        template <typename U>
        explicit CopiedPtr(U* pointer)
        : mOwner( detail::newPtrOwner<T>(pointer, OperatorNewCopy<U>(), OperatorDelete<U>()) )
        , mPointer(pointer)
        {
        }

        template <typename U, typename C>
        CopiedPtr(U* pointer, C cloner)
        : mOwner( detail::newPtrOwner<T>(pointer, cloner, OperatorDelete<U>()) )
        , mPointer(pointer)
        {
        }

        template <typename U, typename C, typename D>
        CopiedPtr(U* pointer, C cloner, D deleter)
        : mOwner( detail::newPtrOwner<T>(pointer, cloner, deleter) )
        , mPointer(pointer)
        {
        }

        CopiedPtr(const CopiedPtr& origin)
        : mOwner(origin ? origin.mOwner->clone() : nullptr)
        , mPointer(origin ? mOwner->getPointer() : nullptr)
        {
        }

        template <typename U>
        CopiedPtr(const CopiedPtr<U>& origin)
        : mOwner(origin ? new detail::PtrIndirection<T, U>(origin.mOwner, detail::CopyTag()) : nullptr)
        , mPointer(origin ? mOwner->getPointer() : nullptr)
        {
        }

        CopiedPtr(CopiedPtr&& source)
        : mOwner(source.mOwner)
        , mPointer(source.mPointer)
        {
            source.mOwner = nullptr;
            source.mPointer = nullptr;
        }

        template <typename U>
        CopiedPtr(CopiedPtr<U>&& source)
        : mOwner(source ? new detail::PtrIndirection<T, U>(source.mOwner, detail::MoveTag()) : nullptr)
        , mPointer(source.mPointer)
        {
            source.mOwner = nullptr;
            source.mPointer = nullptr;
        }

#ifdef AURORA_HAS_VARIADIC_TEMPLATES

        // [Implementation detail]
        // Emplacement constructor: Used to implement makeCopied<T>(args)
        template <typename... Args>
        CopiedPtr(detail::EmplaceTag, Args&&... args)
        : mOwner(new detail::CompactOwner<T>(detail::EmplaceTag(), std::forward<Args>(args)...))
        , mPointer(mOwner->getPointer())
        {
        }

#endif // AURORA_HAS_VARIADIC_TEMPLATES

        CopiedPtr& operator= (const CopiedPtr& origin)
        {
            CopiedPtr(origin).swap(*this);
            return *this;
        }

        template <typename U>
        CopiedPtr& operator= (const CopiedPtr<U>& origin)
        {
            CopiedPtr(origin).swap(*this);
            return *this;
        }

        CopiedPtr& operator= (CopiedPtr&& source)
        {
            CopiedPtr(std::move(source)).swap(*this);
            return *this;
        }

        template <typename U>
        CopiedPtr& operator= (CopiedPtr<U>&& source)
        {
            CopiedPtr(std::move(source)).swap(*this);
            return *this;
        }

        ~CopiedPtr()
        {
            // Destroy owner, whose destructor also deletes the pointer
            delete mOwner;
        }

        void swap(CopiedPtr& other)
        {
            adlSwap(mOwner, other.mOwner);
            adlSwap(mPointer, other.mPointer);
        }

        AURORA_FAKE_DOC(typename std::add_lvalue_reference<T>::type, T&) operator* () const
        {
            assert(mPointer);
            return *mPointer;
        }

        T* operator-> () const
        {
            assert(mPointer);
            return mPointer;
        }

        operator SafeBool() const
        {
            return toSafeBool(mPointer != nullptr);
        }

        T* get() const
        {
            return mPointer;
        }

        void reset()
        {
            CopiedPtr().swap(*this);
        }

        template <typename U>
        void reset(U* pointer)
        {
            CopiedPtr(pointer).swap(*this);
        }

        template <typename U, typename C>
        void reset(U* pointer, C cloner)
        {
            CopiedPtr(pointer, cloner).swap(*this);
        }

        template <typename U, typename C, typename D>
        void reset(U* pointer, C cloner, D deleter)
        {
            CopiedPtr(pointer, cloner, deleter).swap(*this);
        }


    // ---------------------------------------------------------------------------------------------------------------------------
    // Private variables
    private:
        detail::PtrOwnerBase<T>*    mOwner;
        T*                          mPointer;

    template <typename T2>
    friend class CopiedPtr;
};


template <typename T>
void swap(CopiedPtr<T>& lhs, CopiedPtr<T>& rhs)
{
    return lhs.swap(rhs);
}


// For documentation and modern compilers
#ifdef AURORA_HAS_VARIADIC_TEMPLATES

template <typename T, typename... Args>
CopiedPtr<T> makeCopied(Args&&... args)
{
    return CopiedPtr<T>(detail::EmplaceTag(), std::forward<Args>(args)...);
}

// Unoptimized fallback for compilers that don't support variadic templates, emulated by preprocessor metaprogramming
#else  // AURORA_HAS_VARIADIC_TEMPLATES

#include <Aurora/SmartPtr/Detail/Factories.hpp>

// Define metafunction to generate overloads for aurora::CopiedPtr
#define AURORA_DETAIL_COPIEDPTR_FACTORY(n) AURORA_DETAIL_SMARTPTR_FACTORY(CopiedPtr, makeCopied, n)

// Generate code
AURORA_PP_ENUMERATE(AURORA_PP_LIMIT, AURORA_DETAIL_COPIEDPTR_FACTORY)

#endif // AURORA_HAS_VARIADIC_TEMPLATES


} // namespace aurora

#endif // AURORA_COPIEDPTR_HPP