Overload << operator.... sort of...

I'm new to operator overloading, and I don't know if this is possible. I want to create my own stream system to output debug specs to an edit control. I want it to function like this:

Code:

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debugStream ds;

ds << "Current Index: " << currIndex << endl;

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That code would result in that string, then that integer, then that string being sent to a function as parameters. Is this possible?

Yes you can do that. However you would have to basically write your own ostream class one that can handle all data types.

I have something now that works, but it's been basically all guess work.

Code:

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HWND hEdit;

class dStream
{
public:
        dStream();
        ~dStream();
        dStream operator << (char *);
};

dStream::dStream()
{
}

dStream::~dStream()
{
}

dStream dStream::operator <<(char *param)
{
        dStream ds;
        DWORD size;
        size=GetWindowTextLength(hEdit);
        SendMessage(hEdit, EM_SETSEL,size,size);
        SendMessage(hEdit,EM_REPLACESEL,(WPARAM)false, (LPARAM) param);
        return ds;
}

.
.
.

dStream ds;
ds << "hello" << "\r\n";

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It works, but I dont understand some things. When I return an object from the overload function, what happens? At the moment, it's obviously not doing anything useful cause I'm just creating a dummy object. Would there be a use for returning an object though?

Also, how can I enable sending endl to the stream?

You return a reference to the stream object to be used in calling the stream again in a row. Just like with cout.

endl just outputs the '\n' character, then flushes the output buffer.

Quote:

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Originally posted by velius
You return a reference to the stream object to be used in calling the stream again in a row. Just like with cout.

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Is this correct then?

Code:

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dStream dStream::operator <<(char *param)
{
        DWORD size;
        size=GetWindowTextLength(hEdit);
        SendMessage(hEdit, EM_SETSEL,size,size);
        SendMessage(hEdit, EM_REPLACESEL, (WPARAM) false, (LPARAM) param);
        return *this;
}

---

Quote:

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endl just outputs the '\n' character, then flushes the output buffer.

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When I do that I get an error.

Code:

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ds << "byebye" << std::endl;

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Quote:

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error C2679: binary '<<' : no operator defined which takes a right-hand operand of type '' (or there is no acceptable conversion)

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I understand that I may need to overload again, but in what way?

dStream dStream::operator <<(char *param)

should be:

dStream& dStream::operator <<(char *param)