Hi there!
Using pd those days I was missing some function that could perform a floor function. I know it is not much to it, quiet simple too, so I made the extern.
It does work, but I have a problem with it; for it to work I need to send a message "solve" in the first inlet. It's not a big problem but it's weird, cause the operation it's quiet simple. What should I change in the code (above) so I don't need to "bang" the solve message when I use it on Pd?
Thanx so much!

#include <math.h>
#include "m_pd.h"

static t_class *rounder_class;

typedef struct _rounder{
t_object x_obj;
t_float A,B;
t_outlet *result_out;
}t_rounder;

void rounder_solve(t_rounder *x){

t_int result;
result= round(x->A);

outlet_float(x->x_obj.ob_outlet,result);
}

void *rounder_new(t_symbol *s,int argc, t_atom *argv){

t_rounder *x=(t_rounder *)pd_new(rounder_class);

floatinlet_new(&x->x_obj,&x->A);

x->result_out=outlet_new(&x->x_obj, &s_float);

return (void*)x;
}

void rounder_setup(void){
rounder_class = class_new(gensym("rounder"),
(t_newmethod)rounder_new,
0, sizeof(t_rounder),
CLASS_DEFAULT,
A_DEFFLOAT, 0);

class_addmethod(rounder_class,
(t_method)rounder_solve,
gensym("solve"),A_DEFFLOAT,0);
}

oops, actually the topic should be "round external", cause this extern performs a round function!
Some answers please!

Replace the class_addmethod() line with this:

class_addfloat(rounder_class, rounder_float);

This will allow you to have a method that gets triggered when a float is received, in this case the method (function) is named rounder_float. The float will then be passed to the function if you declare it like this:

void rounder_float(t_rounder *x, t_float f)

Maelstrom, you rock!
Thanx so much!