ref: 7a29422cfefaf76315eafa82ca606f9ded9517b3
dir: /lib9/utfecpy.c/
#include "lib9.h" char* utfecpy(char *to, char *e, char *from) { char *end; if(to >= e) return to; end = memccpy(to, from, '\0', e - to); if(end == nil){ end = e; while(end>to && (*--end&0xC0)==0x80) ; *end = '\0'; }else{ end--; } return end; }