XS.xs 

static int consume_latin_byte(U8* in, U8* out) {
    U8 *d;

    if(in[0] > 0x9F) {
        d = uvchr_to_utf8(out, (UV)in[0]);
        *d = '\0';
    }
    else {
        strncpy(out, _ms_map + (in[0] & 0x7F) * 4, 4);
    }
    return(1);
}