Lib.rs

Provides types with unique properties required for SSZ serialization and Merklization:

• FixedVector: A heap-allocated list with a size that is fixed at compile time.
• VariableList: A heap-allocated list that cannot grow past a type-level maximum length.
• BitList: A heap-allocated bitfield that with a type-level maximum length.
• BitVector: A heap-allocated bitfield that with a type-level fixed_ length.

These structs are required as SSZ serialization and Merklization rely upon type-level lengths for padding and verification.

Adheres to the Ethereum 2.0 SSZ specification at v0.12.1.

Example

use ssz_types::*;

pub struct Example {
    bit_vector: BitVector<typenum::U8>,
    bit_list: BitList<typenum::U8>,
    variable_list: VariableList<u64, typenum::U8>,
    fixed_vector: FixedVector<u64, typenum::U8>,
}

let mut example = Example {
    bit_vector: Bitfield::new(),
    bit_list: Bitfield::with_capacity(4).unwrap(),
    variable_list: <_>::from(vec![0, 1]),
    fixed_vector: <_>::from(vec![2, 3]),
};

assert_eq!(example.bit_vector.len(), 8);
assert_eq!(example.bit_list.len(), 4);
assert_eq!(&example.variable_list[..], &[0, 1]);
assert_eq!(&example.fixed_vector[..], &[2, 3, 0, 0, 0, 0, 0, 0]);