latest_gc_info

static VALUE
gc_latest_gc_info(int argc, VALUE *argv, VALUE self)
{
    rb_objspace_t *objspace = &rb_objspace;
    VALUE arg = Qnil;

    if (rb_check_arity(argc, 0, 1) == 1) {
        arg = argv[0];
        if (!SYMBOL_P(arg) && !RB_TYPE_P(arg, T_HASH)) {
            rb_raise(rb_eTypeError, "non-hash or symbol given");
        }
    }
    else {
        arg = rb_hash_new();
    }

    return gc_info_decode(objspace, arg, 0);
}