problems with std.bitmanip.append (bug?)

[Hugo via Digitalmars-d-learn]

On Thursday, 26 March 2015 at 02:39:56 UTC, Steven Schveighoffer 
wrote:
> 
> An array as an output range writes to the front. You can use 
> std.array.Appender to get appending behavior. I know, it's 
> weird.
>
> Alternatively, you can add more bytes to the array, and append 
> to the slice, but that may be ugly/hard to do.
>
> -Steve

Hmm... isnt that't what the std.bitmanip.write function is for? 
It even provides an index.

I could make an 8 byte buffer and then make a slice with the last 
4 bytes and use append there, but it would be rather a hack 
around something that should have worked.

Perhaps I have found a bug. Actually I am not sure because I am 
not yet familiar with the way to use templates, so there is the 
possibility that I am using incorrect arguments.

If only the documentation and/or test units were more clear...