| 12345678910111213141516171819 |
- var $ = require('../internals/export');
- var getBuiltIn = require('../internals/get-built-in');
- var uncurryThis = require('../internals/function-uncurry-this');
- var Symbol = getBuiltIn('Symbol');
- var keyFor = Symbol.keyFor;
- var thisSymbolValue = uncurryThis(Symbol.prototype.valueOf);
- // `Symbol.isRegistered` method
- // https://tc39.es/proposal-symbol-predicates/#sec-symbol-isregistered
- $({ target: 'Symbol', stat: true }, {
- isRegistered: function isRegistered(value) {
- try {
- return keyFor(thisSymbolValue(value)) !== undefined;
- } catch (error) {
- return false;
- }
- }
- });
|