An efficient function to convert a FieldElement in a fixed size hexadecimal representation

felt_to_hex.rs

pub fn to_hex(felt: FieldElement) -> String {
    let bytes = felt.to_bytes_be();
    let mut result = String::with_capacity(bytes.len() * 2 + 2);
    result.push_str("0x");
    for byte in bytes {
        write!(&mut result, "{:02x}", byte).unwrap();
    }
    result
}