1var DataView = require('./_DataView'),
2    Map = require('./_Map'),
3    Promise = require('./_Promise'),
4    Set = require('./_Set'),
5    WeakMap = require('./_WeakMap'),
6    baseGetTag = require('./_baseGetTag'),
7    toSource = require('./_toSource');
8
9/** `Object#toString` result references. */
10var mapTag = '[object Map]',
11    objectTag = '[object Object]',
12    promiseTag = '[object Promise]',
13    setTag = '[object Set]',
14    weakMapTag = '[object WeakMap]';
15
16var dataViewTag = '[object DataView]';
17
18/** Used to detect maps, sets, and weakmaps. */
19var dataViewCtorString = toSource(DataView),
20    mapCtorString = toSource(Map),
21    promiseCtorString = toSource(Promise),
22    setCtorString = toSource(Set),
23    weakMapCtorString = toSource(WeakMap);
24
25/**
26 * Gets the `toStringTag` of `value`.
27 *
28 * @private
29 * @param {*} value The value to query.
30 * @returns {string} Returns the `toStringTag`.
31 */
32var getTag = baseGetTag;
33
34// Fallback for data views, maps, sets, and weak maps in IE 11 and promises in Node.js < 6.
35if ((DataView && getTag(new DataView(new ArrayBuffer(1))) != dataViewTag) ||
36    (Map && getTag(new Map) != mapTag) ||
37    (Promise && getTag(Promise.resolve()) != promiseTag) ||
38    (Set && getTag(new Set) != setTag) ||
39    (WeakMap && getTag(new WeakMap) != weakMapTag)) {
40  getTag = function(value) {
41    var result = baseGetTag(value),
42        Ctor = result == objectTag ? value.constructor : undefined,
43        ctorString = Ctor ? toSource(Ctor) : '';
44
45    if (ctorString) {
46      switch (ctorString) {
47        case dataViewCtorString: return dataViewTag;
48        case mapCtorString: return mapTag;
49        case promiseCtorString: return promiseTag;
50        case setCtorString: return setTag;
51        case weakMapCtorString: return weakMapTag;
52      }
53    }
54    return result;
55  };
56}
57
58module.exports = getTag;
59