System.Linq methods on NS collections is inconsistent

[chamons]

You can call FirstOrDefault on a NSSet but not a NSSet<T> for example. You can not call it on NSMutableArray but you can NSMutableArray<T>.

I've skeched out a reasonable example showing what I've found so far.

Steps to Reproduce

1. Compile https://gist.github.com/chamons/2ef2fe4b0055fc82e13b367d63914c00
2. Compare what you can and can not compile
3. 🤔

Expected Behavior

All NSCollections to allow LINQ methods.

Actual Behavior

Inconsistency

Environment

Master XM/XI

[chamons]

You can work around some of these, say NSSet<T>, by casting, say to NSSet.

[VincentDondain]

Confirmed and marked as enhancement because we're talking about inconsistencies (missing behavior).

[davidjohnoliver]

A note for anyone else who runs into this, you can work around it by supplying the type explicitly, eg:

var first = CollectionView.IndexPathsForVisibleItems.FirstOrDefault<NSIndexPath>();