Formatting & Display

A country code has a single canonical rendering, the two character string. Rendering never allocates on the heap.

Canonical form

CountryCode::as_str() returns the two character string, for example "US". Internally this is a zero cost borrow of the value’s own byte buffer. It never allocates and never panics, because the bytes are guaranteed to be valid ASCII by construction.

use ftracker_identifiers::CountryCode;

let code = CountryCode::parse("us").unwrap();
assert_eq!(code.as_str(), "US"); // normalized to uppercase

If you need raw bytes instead of a &str, CountryCode::as_bytes() returns &[u8; 2] directly.

Display and Debug

CountryCode implements Display by writing its canonical string, so code.to_string() and {} formatting both produce the two character form:

use ftracker_identifiers::CountryCode;

let code = CountryCode::parse("US").unwrap();
assert_eq!(code.to_string(), "US");

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

CountryCode("US")

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