hexutil

Implement common traits for binary representable data.

Use the impl_hex macro to implement the ToHex, FromHex, Display, FromStr, Serialize and Deserialize traits.

This can be done by returning a reference to some bytes:

struct Test([u8; 42]);

hexutil::impl_hex!(Test, 42, |&self| &self.0, |data| Ok(Self(data)));

Or by returning some bytes by value:

struct Test(u128);

hexutil::impl_hex!(Test, 16, |self| self.0.to_le_bytes(), |data| Ok(Self(
    u128::from_le_bytes(data)
)));

Example

struct Test(u16);

hexutil::impl_hex!(Test, 2, |self| self.0.to_le_bytes(), |data| Ok(Self(
    u16::from_le_bytes(data)
)));

let test = Test(0x1234);

// std::fmt::Display
assert_eq!(format!("{}", test), "3412");

// std::string::ToString
let hex = test.to_string();
assert_eq!(hex, "3412");

// std::convert::FromStr
let test: Test = hex.parse().unwrap();
assert_eq!(test, Test(0x1234));

// hexutil::ToHex
let hex = test.to_hex();
assert_eq!(hex, "3412");

// hexutil::FromHex
let test = Test::from_hex(hex.as_bytes()).unwrap();
assert_eq!(test, Test(0x1234));

// hexutil::ParseHex
let test: Test = hex.parse_hex().unwrap();
assert_eq!(test, Test(0x1234));

// serde::Serialize (with serializer.is_human_readable() == true)
let json = serde_json::to_string(&test).unwrap();
assert_eq!(json, r#""3412""#);

// serde::Deserialize (with deserializer.is_human_readable() == true)
let test: Test = serde_json::from_str(&json).unwrap();
assert_eq!(test, Test(0x1234));

// serde::Serialize (with serializer.is_human_readable() == false)
let bin = bincode::serialize(&test).unwrap();
assert_eq!(bin, [0x34, 0x12]);

// serde::Deserialize (with deserializer.is_human_readable() == false)
let test: Test = bincode::deserialize(&bin).unwrap();
assert_eq!(test, Test(0x1234));

Presets

You can append a list of presets what do derive:

Name	Desciption
default	convert and serde
convert	Display and FromStr
Display	Implement the std::fmt::Display trait (enables the to_string() method)
FromStr	Implement the std::convert::FromStr trait (enables the str.parse() method)
serde	Serialize and Deserialize
Serialize	Implement the serde::Serialize trait
Deserialize	Implement the serde::Deserialize trait

Derive only the ToHex, FromHex, Serialize and Deserialize traits:

struct Test([u8; 42]);

hexutil::impl_hex!(Test, 42, |self| self.0, |data| Ok(Self(data)), [serde]);

FromHex Error

The second function returns a Result<Self, FromHexError>:

struct Test([u8; 42]);

hexutil::impl_hex!(Test, 42, |self| self.0, |data| {
    Err(FromHexError::CustomStr("can't create this from hex"))
});

Or use FromHexError::InvalidValue to display a default message:

struct Test([u8; 42]);

hexutil::impl_hex!(Test, 42, |self| self.0, |data| Err(
    FromHexError::InvalidValue
));

One direction only

You can also implement only one direction:

struct Test([u8; 42]);

hexutil::impl_to_hex!(Test, 42, |self| self.0);

struct Test([u8; 42]);

hexutil::impl_from_hex!(Test, 42, |data| Ok(Self(data)));

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.