Mixin template parameter overloading bug?

[Manfred Nowak]

On Sunday, 15 June 2025 at 10:51:37 UTC, Nick Treleaven wrote:

> An untyped parameter does make the literal an actual template:
> ```d
> pragma(msg, __traits(isTemplate, (x) {})); // true
> ```
> It can be instantiated with a type parameter.

Therefore in the case discussed, the code `(_){}' declares a 
template. This template is used as an actual parameter to a 
parameterized mixin.

If used and in general, templates must be instantiated and the 
instantiatons stored for later use.

It seems, that for a parameterized mixin those actual 
instantiatons are not deleted when they do not conform with the 
formal parameter of the mixin.