From d90b71cff68ec3748b9f42063513773da57e01e2 Mon Sep 17 00:00:00 2001 From: Erick Tryzelaar Date: Tue, 1 Jul 2014 07:29:16 -0700 Subject: [PATCH] std: move the hash docstring over to std::hash. --- src/libstd/hash.rs | 53 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-) diff --git a/src/libstd/hash.rs b/src/libstd/hash.rs index fd1bab2dd71..2cc7e70747a 100644 --- a/src/libstd/hash.rs +++ b/src/libstd/hash.rs @@ -8,7 +8,58 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -//! Generic hashing support. +/*! + * 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 `#[deriving(Hash)]`: + * + * # Example + * + * ```rust + * use std::hash; + * use std::hash::Hash; + * + * #[deriving(Hash)] + * struct Person { + * id: uint, + * 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::hash(&person1) != hash::hash(&person2)); + * ``` + * + * If you need more control over how a value is hashed, you need to implement + * the trait `Hash`: + * + * ```rust + * use std::hash; + * use std::hash::Hash; + * use std::hash::sip::SipState; + * + * struct Person { + * id: uint, + * name: String, + * phone: u64, + * } + * + * impl Hash for Person { + * fn hash(&self, state: &mut SipState) { + * 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!(hash::hash(&person1) == hash::hash(&person2)); + * ``` + */ pub use core_collections::hash::{Hash, Hasher, Writer, hash, sip}; -- 2.44.0