`in` parameters made useful

[Jacob Carlborg]

On Friday, 21 August 2020 at 09:37:37 UTC, WebFreak001 wrote:

> For example in Win32 COM IDL files I often see [in] used for 
> input only parameters, can we annotate parameters in D like 
> that without changing calling semantics to document that they 
> are input only parameters and potentially allow optimizations?

You can attach a UDA. It can't be called "in", but perhaps 
"input".

--
/Jacob Carlborg