How to use `format` to repeat a character

[ketmar via Digitalmars-d-learn]

On Monday, 11 July 2016 at 09:31:49 UTC, Ali Çehreli wrote:
> What makes you expect that format should have that feature? :)

the fact that format can insert spaces. it is like: "ok, it can 
do spaces. i bet there should be some way to use any character 
instead of space. after all, the implementation would be the 
same, right?!" and then... oops.

probably this worth a ER.