Expand description
Used to do a cheap mutable-to-mutable reference conversion.
This trait is similar to AsRef
but used for converting between mutable
references. If you need to do a costly conversion it is better to
implement From
with type &mut T
or write a custom function.
Note: This trait must not fail. If the conversion can fail, use a
dedicated method which returns an Option<T>
or a Result<T, E>
.
Generic Implementations
AsMut
auto-dereferences if the inner type is a mutable reference (e.g.:foo.as_mut()
will work the same iffoo
has type&mut Foo
or&mut &mut Foo
)
Examples
Using AsMut
as trait bound for a generic function we can accept all mutable references
that can be converted to type &mut T
. Because Box<T>
implements AsMut<T>
we can
write a function add_one
that takes all arguments that can be converted to &mut u64
.
Because Box<T>
implements AsMut<T>
, add_one
accepts arguments of type
&mut Box<u64>
as well:
fn add_one<T: AsMut<u64>>(num: &mut T) {
*num.as_mut() += 1;
}
let mut boxed_num = Box::new(0);
add_one(&mut boxed_num);
assert_eq!(*boxed_num, 1);
Required Methods
Implementors
impl AsMut<str> for str
impl AsMut<str> for String
impl AsMut<timespec> for TimeSpec
impl AsMut<timeval> for TimeVal
impl AsMut<Vec<u8, Global>> for ByteBuf
impl AsMut<BStr> for BString
impl AsMut<BStr> for [u8]
impl AsMut<[u8]> for BStr
impl AsMut<[u8]> for BString
impl AsMut<[u8]> for BytesMut
impl<'_, T, U> AsMut<U> for &mut T where
T: AsMut<U> + ?Sized,
U: ?Sized,
impl<'s, T> AsMut<[T]> for SliceVec<'s, T>
impl<A> AsMut<[<A as Array>::Item]> for ArrayVec<A> where
A: Array,
impl<A> AsMut<[<A as Array>::Item]> for SmallVec<A> where
A: Array,
impl<A> AsMut<[<A as Array>::Item]> for TinyVec<A> where
A: Array,
impl<I, A> AsMut<[A]> for IndexSlice<I, [A]> where
I: Idx,
impl<I, A> AsMut<[A]> for IndexVec<I, A> where
I: Idx,
impl<I, A> AsMut<IndexSlice<I, [A]>> for IndexVec<I, A> where
I: Idx,
impl<L, R> AsMut<str> for Either<L, R> where
L: AsMut<str>,
R: AsMut<str>,
impl<L, R> AsMut<OsStr> for Either<L, R> where
L: AsMut<OsStr>,
R: AsMut<OsStr>,
Requires crate feature use_std
.
impl<L, R> AsMut<CStr> for Either<L, R> where
L: AsMut<CStr>,
R: AsMut<CStr>,
Requires crate feature use_std
.
impl<L, R> AsMut<Path> for Either<L, R> where
L: AsMut<Path>,
R: AsMut<Path>,
Requires crate feature use_std
.