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"Marcus Kwok" <> wrote in message
news:docgn9$ki3$...
> Jim Langston <> wrote:
>> "Ankit" <> wrote in message
>> news: oups.com...
>>>
>>> I have an old VC++ project code base which I am trying to build and
>>> use. This uses an ostream object. Now in my project, I have overloaded
>>> the leftshift operator ( << ), basically being used to "put" data to
>>> the stream object. However, while I run the app, it does not call the
>>> correct implementation of the operator. For example, say I have
>>> following piece of code:
>>>
>>> ostream o;
>>> int i = 4;
>>> const char* temp = "Test String";
>>>
>>> o << temp;
>>> // this call fails. because it does not call the (const char*)
>>> //implementation, rather calls (const double*) implementation
>>> //for the operator <<
>>
>> Perhaps your problem is coming from the fact that temp is declared as a
>> const. const means it won't change, yet here you're trying to change it.
>
> Where is he changing temp?

O.o Why the heck did I read that as o >> temp;?

Just ignore me. I seem to be 0 for 2 today.

Marcus Kwok <> wrote:
> Where is he changing temp? For reference, this compiles and runs
> perfectly fine for me:

Sorry for the multiple posts. Apparently Google Groups does not honor
supercedes.

--
Marcus Kwok

Ankit wrote:

> Hello,
>
> I have an old VC++ project code base which I am trying to build and
> use. This uses an ostream object. Now in my project, I have overloaded
> the leftshift operator ( << ), basically being used to "put" data to
> the stream object. However, while I run the app, it does not call the
> correct implementation of the operator. For example, say I have
> following piece of code:
>
> ostream o;
> int i = 4;
> const char* temp = "Test String";
>
> o << i;
>
> o << temp;
> // this call fails. because it does not call the (const char*)
> //implementation, rather calls (const double*) implementation
> //for the operator <<

Well, that's not possible -- char* is not convertible to double*
without a cast. Do you perhaps means that it is calling the void*
overload?

Please post your exact code that implements the overloads
and calls them. The above code can't be correct (o can never
be put to any useful purpose).

It's not possible to add overloads to std:perator<< . All you can
do is to define :perator<< for ostream and const char*, and
hope that your compiler selects it instead of std:perator<< .
Try writing your call as:
:perator<<(o, temp);
and see if it then chooses the right functions.

Also, include <iostream> (not iostream.h which is a non-standard
header). You might also find things easier if you don't do a "using
namespace std;" until you get your problem sorted out.

Hi all,

Thanks for all your suggestions. I figured out that the problem was
being caused because the library where the operator << was defined, was
using a /J (default char is unsigned) option while compilation.

This lib was included in the DLL that I was trying to make. However,
the DLL did not have /J option for its build. Thus, the confusion was
being caused due to signed/unsigned chars.

Thanks once again for all your suggestions. I did learn about operator
overloading from the posts

Regards,
Ankit