const-struct-version 0.2.0

A trait plus proc-macro to generate a hash based on the fields of a struct. Useful for intelligently expiring a cache when the stored object changes.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

#![allow(dead_code)]

use const_struct_version::StructVersion;

// TODO: Eventually I'd like named fields to be sorted by field name, so they are consistent across
// differnet orderings.

#[derive(StructVersion)]
struct NamedFieldsStruct {
    a: u32,
    b: f32,
}

#[derive(StructVersion)]
struct NamedFieldsStruct2 {
    b: f32,
    a: u32,
}

fn test_that_versions_are_different() {
    let version = <NamedFieldsStruct as StructVersion>::version();
    let version2 = <NamedFieldsStruct2 as StructVersion>::version();

    // Ensure all are different.
    assert_ne!(version, version2);
}