pred()
Returns the Integer equal to int - 1.
1.pred #=> 0 (-1).pred #=> -2
static VALUE int_pred(VALUE num) { if (FIXNUM_P(num)) { long i = FIX2LONG(num) - 1; return LONG2NUM(i); } return rb_funcall(num, '-', 1, INT2FIX(1)); }