iostream question

iostream question

[Robert Schweikert]

I am trying to compile a large application with gcc 3.2, (porting from 
gcc 2.95.2) and am getting errors like this.

/home/rjschwei/local/include/c++/3.2/backward/iostream.h:35: using
declaration
   `ostream' introduced ambiguous type `ostream'

The application uses iostream.h, converting to iostream is not an option.At first glance it looks like most error come from template files.

Any hints on tracking this problem down are appreciated.

Thanks,
Robert


-- 
Robert Schweikert                   MAY THE SOURCE BE WITH YOU
rjschwei@cox.net                               LINUX

Re: iostream question

[Gabriel Dos Reis]

Robert Schweikert <rjschwei@cox.net> writes:

| I am trying to compile a large application with gcc 3.2, (porting from 
| gcc 2.95.2) and am getting errors like this.
| 
| /home/rjschwei/local/include/c++/3.2/backward/iostream.h:35: using
| declaration
|    `ostream' introduced ambiguous type `ostream'

Did your application already declared ostream before #include <iostream.h>?
(I suspect that is the case).  If so, then, you no option but delete
that forward-declaration.

-- Gaby

Re: iostream question

[Robert Schweikert]

OK,

Are you saying I can no longer forward declare an ostream?

That would mean that for a declaration like so

ostream& operator<< (ostream&, const myClass);

I have to include the iostream header file in my header file. That seems odd. There's got to be a better way.

Robert



Gabriel Dos Reis wrote:

>Robert Schweikert <rjschwei@cox.net> writes:
>
>| I am trying to compile a large application with gcc 3.2, (porting from 
>| gcc 2.95.2) and am getting errors like this.
>| 
>| /home/rjschwei/local/include/c++/3.2/backward/iostream.h:35: using
>| declaration
>|    `ostream' introduced ambiguous type `ostream'
>
>Did your application already declared ostream before #include <iostream.h>?
>(I suspect that is the case).  If so, then, you no option but delete
>that forward-declaration.
>
>-- Gaby
>
>  
>


-- 
Robert Schweikert                   MAY THE SOURCE BE WITH YOU
rjschwei@cox.net                               LINUX

Re: iostream question

[Phil Edwards]

On Wed, Oct 16, 2002 at 08:52:53PM -0400, Robert Schweikert wrote:
> OK,
> 
> Are you saying I can no longer forward declare an ostream?

Yes, but you don't want to forward declare an ostream anymore.

    class ostream;

isn't legal, because it doesn't match the real ostream.


> That would mean that for a declaration like so
> 
> ostream& operator<< (ostream&, const myClass);
> 
> I have to include the iostream header file in my header file. That seems
> odd. There's got to be a better way.

There is, called <iosfwd>.  All the I/O classes, forward declared.


Phil

-- 
I would therefore like to posit that computing's central challenge, viz. "How
not to make a mess of it," has /not/ been met.
                                                 - Edsger Dijkstra, 1930-2002