pub struct BuildHasherDefault<H>(_);
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.
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]) {
unimplemented!()
}
fn finish(&self) -> u64 {
unimplemented!()
}
}
type MyBuildHasher = BuildHasherDefault<MyHasher>;
let hash_map = HashMap::<u32, u32, MyBuildHasher>::default();
Performs copy-assignment from source
. Read more
Type of the hasher that will be created.
This method tests for self
and other
values to be equal, and is used by ==
. Read more
This method tests for !=
.
Formats the value using the given formatter. Read more
Returns the "default value" for a type. Read more
Creates owned data from borrowed data, usually by cloning. Read more
🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
type Error = <U as TryFrom<T>>::Error
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static