New Issue: CG with anonymous interfaces

16414, “vasslitvinov”, “CG with anonymous interfaces”, “2020-09-18T01:26:05Z”

Main issue: #8629

CG (constrained generics) can provide anonymous interfaces with proc and iter constraints.

If all I need is to require proc foo(x) to be available, can I simply write that in the where clause of my CG function and have the compiler create an interface for that? At the call site, the compiler will infer whether that interface is implemented, just like it would for a named interface.

We can use iter constraints analogously for iterators.