Anonymous structure return problem

Anonymous structure return problem

[Dimitry Golubovsky]

Hi,


I am trying to compile the following with egcs 2.91.66 (came with some
Slackware a while ago):

static struct { int __errcode;  int  __result; }  read_int(int fd)
{
          struct { int __errcode;  int  __result; }  ret;
          return ret;
}

This is of course a dummy code (a template, so to speak), but the 
problem is that it does not compile. I do not want to declare a typedef 
for the function's return type, so I define an anonymous structure (the 
function returns a structure, not a pointer). I am getting "incompatible 
types in return" compiler error for the line containing "return ret" 
statement. Why doesn't this work?

Types for ret and for the function are identical as declared.

I would like to avoid explicit declaration of structure type.

Someone also tested the code on gcc 3.2.1 with the same (unsuccessful) 
result.

-- 
Dmitry M. Golubovsky
        South Lyon, MI


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-- 
Dmitry M. Golubovsky
       South Lyon, MI

Re: Anonymous structure return problem

[Daniel Jacobowitz]

On Sun, Mar 09, 2003 at 03:12:54PM -0500, Dimitry Golubovsky wrote:
> Hi,
> 
> 
> I am trying to compile the following with egcs 2.91.66 (came with some
> Slackware a while ago):
> 
> static struct { int __errcode;  int  __result; }  read_int(int fd)
> {
>          struct { int __errcode;  int  __result; }  ret;
>          return ret;
> }
> 
> This is of course a dummy code (a template, so to speak), but the 
> problem is that it does not compile. I do not want to declare a typedef 
> for the function's return type, so I define an anonymous structure (the 
> function returns a structure, not a pointer). I am getting "incompatible 
> types in return" compiler error for the line containing "return ret" 
> statement. Why doesn't this work?
> 
> Types for ret and for the function are identical as declared.
> 
> I would like to avoid explicit declaration of structure type.
> 
> Someone also tested the code on gcc 3.2.1 with the same (unsuccessful) 
> result.

Two structures with the same contents are incompatible in C; you have
to name it, either as a typedef or as a named structure.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer