Macro cformat 

macro_rules! cformat {
    ($ ($ arg : tt) *) => { ... };
}

format! for C strings: builds the formatted String and converts it to a CString in one visibly-named step.

This is the recommended way to build dynamic channel URIs and other C-string arguments. The c-prefix keeps the heap allocation greppable and visible at the call site — important for latency-sensitive code review — while removing the format!(...).into_c_string() noise:

let port = 4040;
let uri = cformat!("aeron:udp?endpoint=localhost:{port}");
assert_eq!(uri.to_bytes(), b"aeron:udp?endpoint=localhost:4040");

The three-tier pattern for C-string arguments (cheapest first):

1. c"aeron:ipc" literals — compile-time &'static CStr, zero runtime cost. Use for every constant channel/name.
2. cformat!(...) — one heap allocation (the formatted String; CString::new reuses its buffer). Use for dynamic URIs built once per stream/reconnect.
3. Reuse — build the CString once, store it, pass &it on every call (zero-copy via &CString → &CStr deref). Use for anything on a repeated path.

Panics if the formatted string contains an interior nul byte.