4 replies to this topic

[belfegor]

I waant to wrap IDirect3DTexture9 object and make it "move capable", to be able to store this into some STL containers.
How i should do this properly as IDirect3DTexture9 is a COM objets witch inherits from IUnknown witch does some reference counting?

class MyTexture
{
private:
    IDirect3DTexture9* tex;

    MyTexture(const MyTexture& o) {} // no copies allowed
    MyTexture& operator = (const MyTexture& o) { return *this; }// no copies allowed

public:
    MyTexture()
    {
        D3DXCreateTextureFromFile(... &tex);
    }

    ~MyTexture()
    {
        tex->Relase();
        tex = nullptr;
    }

    MyTexture(MyTexture&& o) : tex(o.tex) { o.tex = nullptr; }

    MyTexture& operator = (MyTexture&& o)
    {
        if(this != &o)
        {
            tex->Release();// Should release here???
            tex = o.tex;
            o.tex = nullptr;
        }
        return *this;
    }
};

Thanks for your time.

[belfegor]

This seems fine to me:

#include <iostream>
#include <vector>
#include <algorithm>

typedef unsigned long ulong;

class IUnknown
{
private:
    ulong refCnt;
public:
    IUnknown()
    {}

    ulong AddRef()
    {
        return ++refCnt;
    }

    ulong Release()
    {
        if (--refCnt == 0)
        {
            delete this;
            return 0;
        }
        return refCnt;
    }
};

void CreateCOMLikeObject(IUnknown** pp)
{
    *pp = new IUnknown;
    (*pp)->AddRef();
}

class Foo
{
private:
    friend struct smallerData;
    IUnknown* p;
    int data;

    Foo(const Foo& o) {}
    Foo& operator = (const Foo& o) { return *this; }
    Foo() {}

public:
    explicit Foo(int d) : p(nullptr), data(d)
    {
        CreateCOMLikeObject(&p);
    }

    ~Foo()
    {
        if(nullptr != p)
        {
            p->Release();
            p = nullptr;
        }
    }

    Foo(Foo&& o) : p(o.p), data(o.data)
    {
        o.p = nullptr;
    }

    Foo& operator = (Foo&& o)
    {
        if(this != &o)
        {
            p    = o.p;
            data = o.data;
            o.p  = nullptr;
        }
        return *this;
    }

    int get_data() const { return data; }
};

struct smallerData
{
public:
    bool operator () (const Foo& l, const Foo& r) const
    {
        return l.data < r.data;
    }
};

int main()
{
    {
        std::vector<Foo> v;

        for(int i = 0; i < 10; ++i)
        {
            v.push_back(Foo(10 - i));
        }

        std::random_shuffle(v.begin(), v.end());

        std::cout << "shuffled :\t";
        std::for_each(v.begin(), v.end(), [](const Foo& f) { std::cout << f.get_data() << ' '; });
        std::cout << std::endl;

        std::sort(v.begin(), v.end(), smallerData());

        std::cout << "sorted :\t";
        std::for_each(v.begin(), v.end(), [](const Foo& f) { std::cout << f.get_data() << ' '; });
        std::cout << std::endl;
    }

    std::cout << "Press enter to exit...";
    std::cin.ignore();
    return 0;
}

[SiCrane]

Why not use an existing smart pointer like CComPtr?

[belfegor]

I don't like COM , it makes me dizzy. I am trying to see if i can get away from using pointers in STL containers.
See any problems with my latest code?

Thanks for your time.

[Martins Mozeiko]

If you are using IDirect3DTexture9, then you are using COM - or more precisely - you are using COM-like object.
CComPtr has only one thing to do - to mange COM-like objects. So I really don't see any disadvantage of using CComPtr class.

Alternatively you can use boost::intrusive_ptr to do the same job - http://www.gamedev.n...ost__p__4573797