Function encode_event_cpi 

pub fn encode_event_cpi(
    event_tag: u8,
    event_payload: &[u8],
    out: &mut [u8],
) -> Option<usize>

Fill an out buffer with the CPI wire format for an event.

Returns the number of bytes written. Caller picks the buffer size; 2 + 1 + E::PACKED_SIZE is always sufficient. Returns None if the out buffer is too small.

Zero-alloc. Compiles to a pair of copy_from_slice calls.

let mut buf = [0u8; 2 + 1 + Deposited::PACKED_SIZE];
let len = hopper_runtime::cpi_event::encode_event_cpi(
    Deposited::TAG,
    event.as_bytes(),
    &mut buf,
).unwrap();

// Build an InstructionView and invoke_signed from here. The
// sentinel handler accepts the CPI and returns Ok(()).