ref: 43c17be65ab86b88d8e17a0bf2bffa9c253f86f2 dir: /sys/src/cmd/unix/drawterm/libc/runestrlen.c/
#include <u.h> #include <libc.h> long runestrlen(Rune *s) { return runestrchr(s, 0) - s; }