As stated in theserialization guide:

In most cases, this library usesindexedDB storage, which allows any value type. But in special cases (like in Firefox / IE private mode, see thebrowser support guide for details), the library will fall back tolocalStorage, where JSON serialization will happen.

Everything can be serialized (JSON.stringify()), but when you unserialize (JSON.parse()), you'll only get a JSON, ie. a primitive type, an array or aliteral object.

So if you store an instance of a specific class inlocalStorage, likeDate,Map,Set orBlob, what you'll get then with.setItem() won't be aMap,Set orBlob, but just a literal object.

So, it's safer tostick to JSON-compatible values.

The library could add options to manageDate,Map orSet automatically.

It requires:

1. API design,
2. time: I don't have time currently to implement new features, sosponsoring or community PRs are welcomed (after having agreed on the API design)