numeric.c:93
static VALUE
coerce_rescue(x)
    VALUE *x;
{
    volatile VALUE v = rb_inspect(x[1]);

    rb_raise(rb_eTypeError, "%s can't be coerced into %s",
	     rb_special_const_p(x[1])?
	     RSTRING(v)->ptr:
	     rb_obj_classname(x[1]),
	     rb_obj_classname(x[0]));
    return Qnil;		/* dummy */
}
