Struct std::hash::BuildHasherDefault  
1.7.0 · source · [−]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();Trait Implementations
sourceimpl<H> BuildHasher for BuildHasherDefault<H> where
    H: Default + Hasher, 
 
impl<H> BuildHasher for BuildHasherDefault<H> where
    H: Default + Hasher, 
type Hasher = H
type Hasher = H
Type of the hasher that will be created.
sourcefn build_hasher(&self) -> H
 
fn build_hasher(&self) -> H
Creates a new hasher. Read more
sourceimpl<H> Clone for BuildHasherDefault<H>
 
impl<H> Clone for BuildHasherDefault<H>
sourcefn clone(&self) -> BuildHasherDefault<H>
 
fn clone(&self) -> BuildHasherDefault<H>
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
 
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source. Read more
1.9.0 · sourceimpl<H> Debug for BuildHasherDefault<H>
 
impl<H> Debug for BuildHasherDefault<H>
const: unstable · sourceimpl<H> Default for BuildHasherDefault<H>
 
impl<H> Default for BuildHasherDefault<H>
const: unstable · sourcefn default() -> BuildHasherDefault<H>
 
fn default() -> BuildHasherDefault<H>
Returns the “default value” for a type. Read more
1.29.0 · sourceimpl<H> PartialEq<BuildHasherDefault<H>> for BuildHasherDefault<H>
 
impl<H> PartialEq<BuildHasherDefault<H>> for BuildHasherDefault<H>
impl<H> Eq for BuildHasherDefault<H>
Auto Trait Implementations
impl<H> RefUnwindSafe for BuildHasherDefault<H>
impl<H> Send for BuildHasherDefault<H>
impl<H> Sync for BuildHasherDefault<H>
impl<H> Unpin for BuildHasherDefault<H>
impl<H> UnwindSafe for BuildHasherDefault<H>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
    T: ?Sized, 
 
impl<T> BorrowMut<T> for T where
    T: ?Sized, 
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
 
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> ToOwned for T where
    T: Clone, 
 
impl<T> ToOwned for T where
    T: Clone, 
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcefn clone_into(&self, target: &mut T)
 
fn clone_into(&self, target: &mut T)
Uses borrowed data to replace owned data, usually by cloning. Read more