// SPDX-License-Identifier: CC0-1.0 //! Hex encode/decode a type that wraps an array - using implementations of the standard library //! //! `fmt` traits. For an example using the `DisplayHex` trait see `./wrap_array_display_hex.rs`. use core::fmt; use core::str::FromStr; use hex_conservative::{DisplayHex, FromHex, HexToArrayError}; fn main() { let hex = "deadbeefcafebabedeadbeefcafebabedeadbeefcafebabedeadbeefcafebabe"; println!("\nParse from hex: {}\n", hex); let array = <[u8; 32] as FromHex>::from_hex(hex).expect("failed to parse array"); let wrap = Wrap::from_str(hex).expect("failed to parse wrapped array from hex string"); println!("Print an array using traits from the standard libraries `fmt` module along with the provided implementation of `DisplayHex`:\n"); println!("LowerHex: {:x}", array.as_hex()); println!("UpperHex: {:X}", array.as_hex()); println!("Display: {}", array.as_hex()); println!("Debug: {:?}", array.as_hex()); println!("Debug pretty: {:#?}", array.as_hex()); println!("\n"); println!( "Print the wrapped array directly using traits from the standard libraries `fmt` module:\n" ); println!("LowerHex: {:x}", wrap); println!("UpperHex: {:X}", wrap); println!("Display: {}", wrap); println!("Debug: {:?}", wrap); println!("Debug pretty: {:#?}", wrap); // We cannot call `to_lower_hex_string` on the wrapped type to allocate a string, if you wish to // use that trait method see `./wrap_array_display_hex_trait.rs`. let array_hex = array.as_hex().to_string(); let wrap_hex = wrap.to_string(); assert_eq!(array_hex, wrap_hex); } pub struct Wrap([u8; 32]); impl fmt::Debug for Wrap { fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result { fmt::Formatter::debug_tuple(f, "Wrap").field(&self.0.as_hex()).finish() } } impl fmt::Display for Wrap { fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result { fmt::Display::fmt(&self.0.as_hex(), f) } } impl fmt::LowerHex for Wrap { fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result { fmt::LowerHex::fmt(&self.0.as_hex(), f) } } impl fmt::UpperHex for Wrap { fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result { fmt::LowerHex::fmt(&self.0.as_hex(), f) } } impl FromStr for Wrap { type Err = HexToArrayError; fn from_str(s: &str) -> Result { Ok(Self(FromHex::from_hex(s)?)) } }