rdmd with a file with no extension

[XavierAP via Digitalmars-d-learn]

On Wednesday, 1 March 2017 at 16:06:20 UTC, Colin wrote:
> When running a small D program through rdmd, it seems the file 
> needs a .d extension to work.

It looks like the file extension is enforced:
https://dlang.org/dmd-windows.html#switches

Looks like a feature rather than a bug... At the command line, 
both "file" or "file.d" make the compiler look for "file.d". Even 
"file.c" is understood as "file.c.d"