Proposed Phobos equivalent of wcswidth()

[Dominikus Dittes Scherkl]

On Monday, 15 January 2018 at 15:08:24 UTC, Kagamin wrote:
> columnWidth as it only makes sense for column-oriented text 
> display.

I think displayWidth is better, because "width" is directly 
linked to hozizontal direction (else it would be called hight), 
and setting text in colums would still take additional steps to 
be set correct.
Also "display" indicates that it has nothing to do with the 
string length, which is good to avoid confusion.