Attribute Macro byte_string

#[byte_string]

Proc macro that can generate multiple helper functions and traits for types that wrap an array, Vec, or BoundedVec of bytes. What code is generated by the macro is controlled by passing the following arguments:

• debug: implements Debug that uses hex to encode the bytes
• hex_serialize: implements serde::Serialize that encode the bytes to a hex string as intermediate format. This implementation is useful for saving bytes in Json and similar formats.
• hex_deserialize: implements serde::Deserialize that decodes the type from a string containig hex-encoded bytes. This implementation is useful for decoding hex data from Json and similar formats.
• from_num: implements From<u64>
• from_bytes: implements either [From<&[u8]>] or [TryFrom<&[u8]] depending on whether the the type can be infallibly (Vec) or fallibly (array, BoundedVec) cast from a byte slice.
• decode_hex: adds functions decode_hex and decode_hex_unsafe that decode the type from a &str and a FromStr implementation equivalent to calling decode_hex.
• to_hex_string: adds a function to_hex_string that returns the inner bytes as a hex string.
• as_ref: generates [AsRef<[u8]>] implementation

Note: As the code generated by this macro is meant to be no_std-compatible, some of the options require alloc crate to be available in the scope where the code is generated.

Example

extern crate alloc;
use byte_string_derive::byte_string;
use sp_core::{ ConstU32, bounded_vec::BoundedVec };

#[byte_string(debug, hex_serialize, hex_deserialize, from_num, from_bytes, decode_hex, to_hex_string, as_ref)]
pub struct MyArrayBytes([u8; 32]);

#[byte_string(debug, hex_serialize, hex_deserialize, from_num, from_bytes, decode_hex, to_hex_string, as_ref)]
pub struct MyVecBytes(Vec<u8>);

#[byte_string(from_bytes)]
pub struct MyBoundedVecBytes(BoundedVec<u8, ConstU32<32>>);