> -----Original Message-----
> From: Scott C. Gray [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, August 24, 2000 11:52 PM
> To: Bernard Dautrevaux
> Cc: [EMAIL PROTECTED]
> Subject: RE: Tables of function pointers
>
>
> On Thu, 24 Aug 2000, Bernard Dautrevaux wrote:
>
> > Probably the simplest (and more protable) cure would be to have an
> > 'init_function_table' function that initialize the function
> array, like:
> >
> > void init_function_table() {
> > static int initialized = 0;
> > if (initialized) return;
> > sg_func_table[0] = function_0;
> > sg_func_table[1] = function_1;
> > sg_func_table[2] = function_2;
> > sg_func_table[3] = function_3;
> > initialized = 1;
> > }
> >
> > and either call it at the very beginning of your main
> program or, if it is a
> > general purpose library used in numerous programs and
> performance is not too
> > critical, call it at the very beginning of call_function
> (anyway any good C
> > compiler like gcc should be able to integrate it in-line,
> especially if
> > declared static, so the cost is only a test and branch).
>
> That will work, but unfortunately, the tables that I have have
> ~250 function pointers in them, so this method is a little bit
> awkward and relatively error prone...it is much easier to
> just edit the static array.
>
> But, if I get really stuck I may just do this.
I *know* this is kludgy, but a little CPP trick may help:
void init_function_table() {
static int initialized = 0;
int i = 0;
if (initialized) return;
#define Set(f) sg_func_table[i++] = f;
Set(function_0);
Set(function_1);
Set(function_2);
Set(function_3);
#undef Set
initialized = 1;
}
I'm sure you're able to write the global replace for your favorite editor to
change automatically the array initializer in the list of Set() calls... so
this is perhaps a little bit less readable, but not more error prone
although I will not argue it's elegant :-)
Regards,
Bernard
--------------------------------------------
Bernard Dautrevaux
Microprocess Ingéniérie
97 bis, rue de Colombes
92400 COURBEVOIE
FRANCE
Tel: +33 (0) 1 47 68 80 80
Fax: +33 (0) 1 47 88 97 85
e-mail: [EMAIL PROTECTED]
[EMAIL PROTECTED]
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