Re: sizeof gpointer

[mcmahill mtl mit edu]

On Tue, 20 Aug 2002, Olexiy Avramchenko wrote:

> vladimir wrote:
>
> > Hi,
> > Great Free software developers!
> > I really need help on this one :)
> >
> > i have:
> >
> >     void func (gpointer data)
> >     {
> >         /* code ... */
> >     }
> >
> > How can i get size of data in bytes ? 
>
> The only one way I see is to pass a pointer to a structure like this:
>
> typedef struct __my_fun_struct
> {
>         guint        size;        /* This's always the first field, 
> initialized with data size. */
>         gpointer   *data;     /* Or smth else you need */
> } MY_FUN_STRUCT;
>
> > if I do sizeof ("text") i will get 5
> > if I do sizeof (255) i will get 4
> > if I do sizeof (12345678.987654321) i will get 8...
> >
> > But if i do sizeof (data) i get crazy numbers :( (data is a gpointer) 
>
> Hmm, crazy ? sizeof(gpointer) will return the constant number wich 
> depends on your
> architecture (== 4 for x86).

and 8 for alpha and sparc64, so be sure you're not counting on a fixed
value here if you want any sort of portability.

-dan