Trait core::convert::AsRef
[−]
[src]
pub trait AsRef<T: ?Sized> { fn as_ref(&self) -> &T; }
A cheap, reference-to-reference conversion.
AsRef
is very similar to, but different than, Borrow
. See
the book for more.
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>
.
Examples
Both String
and &str
implement AsRef<str>
:
fn is_hello<T: AsRef<str>>(s: T) { assert_eq!("hello", s.as_ref()); } let s = "hello"; is_hello(s); let s = "hello".to_string(); is_hello(s);
Generic Impls
AsRef
auto-dereference if the inner type is a reference or a mutable reference (eg:foo.as_ref()
will work the same iffoo
has type&mut Foo
or&&mut Foo
)
Required Methods
fn as_ref(&self) -> &T
Performs the conversion.
Implementors
impl<'a, T: ?Sized, U: ?Sized> AsRef for &'a T where T: AsRef<U>
impl<'a, T: ?Sized, U: ?Sized> AsRef for &'a mut T where T: AsRef<U>
impl<T> AsRef for [T]
impl AsRef for str
impl<T> AsRef for [T; 0]
impl<T> AsRef for [T; 1]
impl<T> AsRef for [T; 2]
impl<T> AsRef for [T; 3]
impl<T> AsRef for [T; 4]
impl<T> AsRef for [T; 5]
impl<T> AsRef for [T; 6]
impl<T> AsRef for [T; 7]
impl<T> AsRef for [T; 8]
impl<T> AsRef for [T; 9]
impl<T> AsRef for [T; 10]
impl<T> AsRef for [T; 11]
impl<T> AsRef for [T; 12]
impl<T> AsRef for [T; 13]
impl<T> AsRef for [T; 14]
impl<T> AsRef for [T; 15]
impl<T> AsRef for [T; 16]
impl<T> AsRef for [T; 17]
impl<T> AsRef for [T; 18]
impl<T> AsRef for [T; 19]
impl<T> AsRef for [T; 20]
impl<T> AsRef for [T; 21]
impl<T> AsRef for [T; 22]
impl<T> AsRef for [T; 23]
impl<T> AsRef for [T; 24]
impl<T> AsRef for [T; 25]
impl<T> AsRef for [T; 26]
impl<T> AsRef for [T; 27]
impl<T> AsRef for [T; 28]
impl<T> AsRef for [T; 29]
impl<T> AsRef for [T; 30]
impl<T> AsRef for [T; 31]
impl<T> AsRef for [T; 32]
impl AsRef for str