First-class polymorphic lamdas?

[Vladimir Panteleev via Digitalmars-d]

On Friday, 3 June 2016 at 11:11:50 UTC, Vladimir Panteleev wrote:
> For some reason I didn't realize you can also create a value 
> type templated functor by using explicitly nested structs. I 
> had stumbled upon the new feature from 
> https://github.com/dlang/dmd/pull/5518 by accident while 
> working on something similar (heterogenous iteration and 
> range-like composition, e.g. over struct fields). Will post 
> that here later today.

https://github.com/CyberShadow/ae/blob/master/utils/meta/chain.d