Why not delegate to this.constructor

[syg]

To support Type II but not Type III, one obvious thing is to delegate to this.constructor.

I'd like to capture here that delegating to this.constructor is almost definitely not web compatible. Two data points:

1. Microsoft tried to do this in the ES6 era and had to unship due to breakage. Would be great if someone could dig up the history here...

2. There is a V8 use counter that counts modifications to .constructor of Arrays instances: https://chromestatus.com/metrics/feature/timeline/popularity/1394. That is an astonishing number of hits. I took a look at the top URL below, https://articlewipe.com. It's doing some kind of mix-in pattern where the .constructor is overridden. Crucially, that overridden .constructor[@@species] is undefined.

[syg]

@rwaldron also found this gem: https://github.com/tc39/notes/blob/master/meetings/2014-11/nov-18.md#46-zepto-broken-by-new-thisconstruct-usage-in-some-arrayprototype-methods