> Get the visual width of the widest line in a string - the number of columns required to display it
Some Unicode characters are [fullwidth](https://en.wikipedia.org/wiki/Halfwidth_and_fullwidth_forms) and use double the normal width. [ANSI escape codes](http://en.wikipedia.org/wiki/ANSI_escape_code) are stripped and doesn't affect the width.
Useful to be able to know the maximum width a string will take up in the terminal.