+ // UTF8 uses at most 4 bytes to represent one UCS4 code point
+ // (see RFC 3629). RFC 2279 specifies 6 bytes, but that
+ // information is outdated, and RFC 2279 has been superseded by
+ // RFC 3629.
+ // All other encodings encode one UCS4 code point in one byte
+ // (and can therefore only encode a subset of UCS4)
+ return utf8_ ? 4 : 1;