Function JS_IsUndefined

third-party/quickjs/include/quickjs/quickjs.h:587–589

}

static inline JS_BOOL JS_IsUndefined(JSValueConst v) {
    return JS_VALUE_GET_TAG(v) == JS_TAG_UNDEFINED;
}

static inline JS_BOOL JS_IsException(JSValueConst v) {
    return js_unlikely(JS_VALUE_GET_TAG(v) == JS_TAG_EXCEPTION);