High-level wrapper for readline package

[Nordlöw via Digitalmars-d-learn]

On Thursday, 7 September 2017 at 16:23:46 UTC, Adam D. Ruppe 
wrote:
> On Thursday, 7 September 2017 at 16:18:09 UTC, bauss wrote:
>> Isn't it pointless to make "prompt" in?
>
> No, it promises the function isn't doing anything weird to it 
> (modify, which immutable covers, but also scope.. .unless dmd 
> changed that), which means a copy of the pointer won't be 
> stored either. Important to realize with C cuz then you know it 
> is ok to use a temporary to it.

But I believe it's ok to relax it from `string` to 
`const(char)[]`, right?