typedef and declaration of function

[Ron Natalie]

Re: typedef and declaration of function


"Vu Pham" <vu@sivell.co m> wrote in message news:bu4b4v$do1 q2$1@ID-219297.news.uni-berlin.de...
[color=blue]
>
> I use c++ for the implementation file, but that function needs to be
> exported ( from an.so ) and I use extern "C" { } in the declaration file (
> .h ) to prevent the name mangling.[/color]

extern "C" doesn't change the language. Only the linkage. In C++ that's
a function with no arguments.

[Nick Hounsome]

Re: typedef and declaration of function


"Vu Pham" <vu@sivell.co m> wrote in message
news:bu4dee$dui pe$1@ID-219297.news.uni-berlin.de...[color=blue]
>
> "Ron Natalie" <ron@sensor.com > wrote in message
> news:400565ec$0 $71404$9a6e19ea @news.newshosti ng.com...[color=green]
> >
> > "Vu Pham" <vu@sivell.co m> wrote in message[/color]
> news:bu49bv$ddd ep$1@ID-219297.news.uni-berlin.de...[color=green][color=darkred]
> > >
> > > Is there any difference between these two declarations :
> > >
> > > 1.
> > > void * functionA( char * p, int s, int * e );
> > >
> > > and
> > > 2.
> > > typedef void * ( *functionA_t)( char * p, int s, int * e );
> > > functionA_t functionA();[/color]
> >
> > Yes, the second defines a function called functionA that returns a[/color][/color]
pointer[color=blue][color=green]
> > to function. functionA_t is type pointer to function.
> >
> > You could
> > typedef void (functionA_t) (char*, int, int*);
> > functionA_t functionA; // note no parens.
> >[/color]
>
> Thanks, Ron. I think you mean
>
> typedef void* (functionA_t) (char*, int, int*);[/color]

Or even just
typedef void* functionA_t(cha r*,int,int*);

But note that you cannot use the typedef to define the function:

functionA_t f; // OK decl
functionA_t f { } // ill formed defn