12345678910111213141516171819 |
- var fails = require('../internals/fails');
- var wellKnownSymbol = require('../internals/well-known-symbol');
- var V8_VERSION = require('../internals/engine-v8-version');
- var SPECIES = wellKnownSymbol('species');
- module.exports = function (METHOD_NAME) {
- // We can't use this feature detection in V8 since it causes
- // deoptimization and serious performance degradation
- // https://github.com/zloirock/core-js/issues/677
- return V8_VERSION >= 51 || !fails(function () {
- var array = [];
- var constructor = array.constructor = {};
- constructor[SPECIES] = function () {
- return { foo: 1 };
- };
- return array[METHOD_NAME](Boolean).foo !== 1;
- });
- };
|