Struct core::hash::BuildHasherDefault 1.7.0[−][src]
pub struct BuildHasherDefault<H>(_);
Expand description
Used to create a default BuildHasher instance for types that implement
Hasher and Default.
BuildHasherDefault<H> can be used when a type H implements Hasher and
Default, and you need a corresponding BuildHasher instance, but none is
defined.
Any BuildHasherDefault is zero-sized. It can be created with
default. When using BuildHasherDefault with HashMap or
HashSet, this doesn’t need to be done, since they implement appropriate
Default instances themselves.
Examples
Using BuildHasherDefault to specify a custom BuildHasher for
HashMap:
use std::collections::HashMap; use std::hash::{BuildHasherDefault, Hasher}; #[derive(Default)] struct MyHasher; impl Hasher for MyHasher { fn write(&mut self, bytes: &[u8]) { // Your hashing algorithm goes here! unimplemented!() } fn finish(&self) -> u64 { // Your hashing algorithm goes here! unimplemented!() } } type MyBuildHasher = BuildHasherDefault<MyHasher>; let hash_map = HashMap::<u32, u32, MyBuildHasher>::default();Run
Trait Implementations
Returns the “default value” for a type. Read more