43 lines
996 B
Plaintext
43 lines
996 B
Plaintext
'use strict';
|
|
|
|
var $WeakMap = typeof WeakMap === 'function' && WeakMap.prototype ? WeakMap : null;
|
|
var $WeakSet = typeof WeakSet === 'function' && WeakSet.prototype ? WeakSet : null;
|
|
|
|
var exported;
|
|
|
|
if (!$WeakMap) {
|
|
// eslint-disable-next-line no-unused-vars
|
|
exported = function isWeakMap(x) {
|
|
// `WeakMap` is not present in this environment.
|
|
return false;
|
|
};
|
|
}
|
|
|
|
var $mapHas = $WeakMap ? $WeakMap.prototype.has : null;
|
|
var $setHas = $WeakSet ? $WeakSet.prototype.has : null;
|
|
if (!exported && !$mapHas) {
|
|
// eslint-disable-next-line no-unused-vars
|
|
exported = function isWeakMap(x) {
|
|
// `WeakMap` does not have a `has` method
|
|
return false;
|
|
};
|
|
}
|
|
|
|
module.exports = exported || function isWeakMap(x) {
|
|
if (!x || typeof x !== 'object') {
|
|
return false;
|
|
}
|
|
try {
|
|
$mapHas.call(x, $mapHas);
|
|
if ($setHas) {
|
|
try {
|
|
$setHas.call(x, $setHas);
|
|
} catch (e) {
|
|
return true;
|
|
}
|
|
}
|
|
return x instanceof $WeakMap; // core-js workaround, pre-v3
|
|
} catch (e) {}
|
|
return false;
|
|
};
|