Pattern matching is-expressions

[Dennis]

On Wednesday, 19 August 2020 at 12:03:59 UTC, Stefan Koch wrote:
> Does a limited pattern matching still fulfill a desirable power 
> to complexity ratio though?

If D were to be rebuilt from the ground up with first-class 
types, things could definitely be simplified. The existence of 
meta-programming libraries wrapping traits and is-expressions is 
a sign that D's introspection is not intuitive or ergonomic.

https://code.dlang.org/packages/bolts
https://code.dlang.org/packages/mirror

However, considering the current template parameter system is so 
deeply ingrained into the D language and is-expressions simply 
leverage most of that, I don't think we should do away with 
is-expressions.