ref: 84f6061a92d92f6f0136f7d6ab42fa03c38d5a78 dir: /sys/src/cmd/unix/drawterm/libc/runestrlen.c/
#include <u.h> #include <libc.h> long runestrlen(Rune *s) { return runestrchr(s, 0) - s; }