Formatting & Display

A CFI has a single canonical rendering, the 6-character string. Rendering never allocates on the heap.

Canonical form

Cfi::as_str() returns the 6-character string, e.g. "ESVUFR". Internally this is a zero-cost borrow of the identifier’s own byte buffer. It never allocates and never panics, because the bytes are guaranteed to be valid ASCII by construction.

use ftracker_identifiers::Cfi;

let cfi = Cfi::parse("esvufr").unwrap();
assert_eq!(cfi.as_str(), "ESVUFR"); // normalized to uppercase

If you need raw bytes instead of a &str, Cfi::as_bytes() returns &[u8; 6] directly.

Display and Debug

Cfi implements Display by writing its canonical string, so cfi.to_string() and {} formatting both produce the 6-character form:

use ftracker_identifiers::Cfi;

let cfi = Cfi::parse("ESVUFR").unwrap();
assert_eq!(cfi.to_string(), "ESVUFR");

Debug wraps the same string in a readable tuple-struct style, which is what you’ll see in assert_eq! failure messages, logs, and {:?} output:

Cfi("ESVUFR")

This makes a mismatched or unexpected Cfi easy to spot at a glance in test output or logs, without needing to manually reformat raw bytes.