Ruby » Ruby 1.8

static VALUE

fix_gcd(int argc, VALUE *argv, VALUE self) {

if ( argc != 1 ) {

rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)", argc, 1);

} else {

/* Handle Fixnum#gcd(Fixnum) here.

* Note: Cannot handle values <= FIXNUM_MIN here due to overflow during negation.

*/

long a, b;

if ( FIXNUM_P(argv[0]) && (a = FIX2LONG(self)) > FIXNUM_MIN && (b = FIX2LONG(argv[0])) > FIXNUM_MIN ) {

long min = a < 0 ? - a : a;

long max = b < 0 ? - b : b;

while ( min > 0 ) {

long tmp = min;

min = max % min;

max = tmp;

}

return LONG2FIX(max);

} else {

/* Delegate to Integer#gcd. */

return rb_call_super(1, argv);

}

}

}

rb_define_method(rb_cFixnum, "gcd", fix_gcd, -1);