pub fn peek_tag(payload: &[u8]) -> Option<CodecTag>Expand description
Peek at the first byte of a tile payload and return the codec tag.
Returns Some(tag) for a recognized new-format tag byte.
Returns None for an empty payload or any unrecognized byte (including
former msgpack map-start bytes 0x80–0x8f, 0xde, 0xdf) — callers must
surface a SegmentCorruption error.