It might seem unsound but it’s the concept we’ve built our terminals around.

And there are already definitions and APIs to decide the terminal cell width of different Unicode characters.

I’m not saying it’s easy, because you end up with 3 different string widths:

1. memory length in bytes

2. Number of Unicode characters (which is annoyingly also different to the number of Unicode code points since some codes can be combined)

3. terminal cell width

But as annoying as it is, there are a few relatively mature libraries you can use to solve this problem.