pub fn ctor_header<M: Into<Option<[u8; 4]>>>(
buf: &mut [u8],
fin: bool,
rsv1: bool,
rsv2: bool,
rsv3: bool,
mask_key: M,
opcode: OpCode,
payload_len: u64,
) -> &[u8] ⓘExpand description
write header without allocation