source: imaps-frontend/node_modules/is-set/index.js@ d565449

'use strict';

var $Map = typeof Map === 'function' && Map.prototype ? Map : null;
var $Set = typeof Set === 'function' && Set.prototype ? Set : null;

var exported;

if (!$Set) {
        /** @type {import('.')} */
        // eslint-disable-next-line no-unused-vars
        exported = function isSet(x) {
                // `Set` is not present in this environment.
                return false;
        };
}

var $mapHas = $Map ? Map.prototype.has : null;
var $setHas = $Set ? Set.prototype.has : null;
if (!exported && !$setHas) {
        /** @type {import('.')} */
        // eslint-disable-next-line no-unused-vars
        exported = function isSet(x) {
                // `Set` does not have a `has` method
                return false;
        };
}

/** @type {import('.')} */
module.exports = exported || function isSet(x) {
        if (!x || typeof x !== 'object') {
                return false;
        }
        try {
                $setHas.call(x);
                if ($mapHas) {
                        try {
                                $mapHas.call(x);
                        } catch (e) {
                                return true;
                        }
                }
                // @ts-expect-error TS can't figure out that $Set is always truthy here
                return x instanceof $Set; // core-js workaround, pre-v2.5.0
        } catch (e) {}
        return false;
};