Trait nom::lib::std::prelude::v1::rust_2018::AsMut 1.0.0[−][src]
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
Loading content...Implementations on Foreign Types
impl<T> AsMut<[T]> for [T]
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impl<'_, T, U> AsMut<U> for &'_ mut T where
T: AsMut<U> + ?Sized,
U: ?Sized,
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T: AsMut<U> + ?Sized,
U: ?Sized,
impl AsMut<str> for str
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impl<T, const N: usize> AsMut<[T]> for [T; N]
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Loading content...Implementors
impl AsMut<str> for String
1.43.0[src]
impl<T, A> AsMut<[T]> for Vec<T, A> where
A: Allocator,
1.5.0[src]
A: Allocator,
impl<T, A> AsMut<Vec<T, A>> for Vec<T, A> where
A: Allocator,
1.5.0[src]
A: Allocator,
impl<T, A> AsMut<T> for Box<T, A> where
T: ?Sized,
A: Allocator,
1.5.0[src]
T: ?Sized,
A: Allocator,