2 unstable releases
0.2.0 | Jul 21, 2019 |
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0.1.0 | Jun 28, 2019 |
#79 in #price
4KB
keyby
An attribute macro for hashing on a specific field of a struct.
Example
#[macro_use]
extern crate keyby;
use std::collections::hash_map::DefaultHasher;
#[key_by(id)]
pub struct Item {
id: u64,
price: u32,
}
fn main() {
let i1 = Item { id: 1, price: 20 };
let i2 = Item { id: 2, price: 150 };
let i3 = Item { id: 1, price: 50 };
assert_eq!(calc_hash(&i1), calc_hash(&i3));
assert!(calc_hash(&i1) != calc_hash(&i2));
}
fn calc_hash<T: std::hash::Hash>(t: &T) -> u64 {
use std::hash::Hasher;
let mut s = DefaultHasher::new();
t.hash(&mut s);
s.finish()
}
Dependencies
~2MB
~47K SLoC