Fake IFTI-compatible struct constructors

[Basile B.]

On Saturday, 1 May 2021 at 21:57:54 UTC, Chad Joan wrote:
> I came up with a couple techniques for making it seem like 
> templated structs deduce their template parameters from 
> constructor invocations. These are given further down in the 
> post.
> ...
>
> However, this was not to be. Rather, this setup doesn't work at 
> all, because IFTI doesn't seem to work on function-templates 
> with alias parameters.

Yes your observation is correct. That should work but this is 
currently not implemented and referenceced as [issue 
20877](https://issues.dlang.org/show_bug.cgi?id=20877)