Function ws_tool::frame::ctor_header

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] 

write header without allocation