[estebank]

There's a "trick" that works somewhat well for some compound emoji like "family": replace ZWJs with whitespace. Emoji width is not standardized because it depends on platform, fonts available, shell and terminal emulator, but almost no terminal supports compound emoji correctly. Because of how they were designed, most terminals will print the emoji as its component parts. If you need to do something like underline a piece of text (like rustc has to) we decompose them ourselves, and then it is a more tractable problem to know what the width of a char is (0, 1 or 2, and var width for tabs, which we just transform to a hardcoded 4—incorrect but usable). This can still be incorrect, on specific terminals, but works well enough on most.