Module core::hash
[−]
[src]
Generic hashing support.
This module provides a generic way to compute the hash of a value. The
simplest way to make a type hashable is to use #[derive(Hash)]
:
Examples
fn main() { use std::hash::{Hash, SipHasher, Hasher}; #[derive(Hash)] struct Person { id: u32, name: String, phone: u64, } let person1 = Person { id: 5, name: "Janet".to_string(), phone: 555_666_7777 }; let person2 = Person { id: 5, name: "Bob".to_string(), phone: 555_666_7777 }; assert!(hash(&person1) != hash(&person2)); fn hash<T: Hash>(t: &T) -> u64 { let mut s = SipHasher::new(); t.hash(&mut s); s.finish() } }use std::hash::{Hash, SipHasher, Hasher}; #[derive(Hash)] struct Person { id: u32, name: String, phone: u64, } let person1 = Person { id: 5, name: "Janet".to_string(), phone: 555_666_7777 }; let person2 = Person { id: 5, name: "Bob".to_string(), phone: 555_666_7777 }; assert!(hash(&person1) != hash(&person2)); fn hash<T: Hash>(t: &T) -> u64 { let mut s = SipHasher::new(); t.hash(&mut s); s.finish() }
If you need more control over how a value is hashed, you need to implement
the trait Hash
:
use std::hash::{Hash, Hasher, SipHasher}; struct Person { id: u32, name: String, phone: u64, } impl Hash for Person { fn hash<H: Hasher>(&self, state: &mut H) { self.id.hash(state); self.phone.hash(state); } } let person1 = Person { id: 5, name: "Janet".to_string(), phone: 555_666_7777 }; let person2 = Person { id: 5, name: "Bob".to_string(), phone: 555_666_7777 }; assert_eq!(hash(&person1), hash(&person2)); fn hash<T: Hash>(t: &T) -> u64 { let mut s = SipHasher::new(); t.hash(&mut s); s.finish() }
Reexports
use prelude::v1::*; |
use marker; |
use mem; |
Modules
impls | |
sip |
An implementation of SipHash 2-4. |
Structs
BuildHasherDefault |
A structure which implements |
SipHasher |
An implementation of SipHash 2-4. |
Traits
BuildHasher |
A |
Hash |
A hashable type. |
Hasher |
A trait which represents the ability to hash an arbitrary stream of bytes. |
HashState |
[Deprecated] Deprecated, renamed to |