1.0.0[][src]Trait core::convert::AsRef

pub trait AsRef<T: ?Sized> {
    fn as_ref(&self) -> &T;
}

A cheap reference-to-reference conversion. Used to convert a value to a reference value within generic code.

AsRef is very similar to, but serves a slightly different purpose than, Borrow.

AsRef is to be used when wishing to convert to a reference of another type. Borrow is more related to the notion of taking the reference. It is useful when wishing to abstract over the type of reference (&T, &mut T) or allow both the referenced and owned type to be treated in the same manner.

The key difference between the two traits is the intention:

See the book for a more detailed comparison.

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

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);Run

Required Methods

Performs the conversion.

Implementors

impl AsRef<[u8]> for str
[src]

impl AsRef<str> for str
[src]

impl<T> AsRef<[T]> for [T; 0]
[src]

impl<T> AsRef<[T]> for [T; 1]
[src]

impl<T> AsRef<[T]> for [T; 2]
[src]

impl<T> AsRef<[T]> for [T; 3]
[src]

impl<T> AsRef<[T]> for [T; 4]
[src]

impl<T> AsRef<[T]> for [T; 5]
[src]

impl<T> AsRef<[T]> for [T; 6]
[src]

impl<T> AsRef<[T]> for [T; 7]
[src]

impl<T> AsRef<[T]> for [T; 8]
[src]

impl<T> AsRef<[T]> for [T; 9]
[src]

impl<T> AsRef<[T]> for [T; 10]
[src]

impl<T> AsRef<[T]> for [T; 11]
[src]

impl<T> AsRef<[T]> for [T; 12]
[src]

impl<T> AsRef<[T]> for [T; 13]
[src]

impl<T> AsRef<[T]> for [T; 14]
[src]

impl<T> AsRef<[T]> for [T; 15]
[src]

impl<T> AsRef<[T]> for [T; 16]
[src]

impl<T> AsRef<[T]> for [T; 17]
[src]

impl<T> AsRef<[T]> for [T; 18]
[src]

impl<T> AsRef<[T]> for [T; 19]
[src]

impl<T> AsRef<[T]> for [T; 20]
[src]

impl<T> AsRef<[T]> for [T; 21]
[src]

impl<T> AsRef<[T]> for [T; 22]
[src]

impl<T> AsRef<[T]> for [T; 23]
[src]

impl<T> AsRef<[T]> for [T; 24]
[src]

impl<T> AsRef<[T]> for [T; 25]
[src]

impl<T> AsRef<[T]> for [T; 26]
[src]

impl<T> AsRef<[T]> for [T; 27]
[src]

impl<T> AsRef<[T]> for [T; 28]
[src]

impl<T> AsRef<[T]> for [T; 29]
[src]

impl<T> AsRef<[T]> for [T; 30]
[src]

impl<T> AsRef<[T]> for [T; 31]
[src]

impl<T> AsRef<[T]> for [T; 32]
[src]

impl<T> AsRef<[T]> for [T]
[src]

impl<T, '_> AsRef<[T]> for Iter<'_, T>
[src]

impl<T: ?Sized, U: ?Sized, '_> AsRef<U> for &'_ T where
    T: AsRef<U>, 
[src]

impl<T: ?Sized, U: ?Sized, '_> AsRef<U> for &'_ mut T where
    T: AsRef<U>, 
[src]