1.0.0[−][src]Trait std::convert::AsRef  
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:
- Use AsRefwhen the goal is to simply convert into a reference
- Use Borrowwhen the goal is related to writing code that is agnostic to the type of borrow and whether it is a reference or value
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
- AsRefauto-dereferences if the inner type is a reference or a mutable reference (e.g.:- foo.as_ref()will work the same if- foohas type- &mut Fooor- &&mut Foo)
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
Implementors
impl AsRef<[u8]> for str[src] 
impl AsRef<[u8]> for strimpl AsRef<[u8]> for String[src] 
impl AsRef<[u8]> for Stringimpl AsRef<str> for str[src] 
impl AsRef<str> for strimpl AsRef<str> for String[src] 
impl AsRef<str> for Stringimpl AsRef<CStr> for CStr[src] 
impl AsRef<CStr> for CStrimpl AsRef<CStr> for CString[src] 
impl AsRef<CStr> for CStringimpl AsRef<OsStr> for str[src] 
impl AsRef<OsStr> for strimpl AsRef<OsStr> for OsStr[src] 
impl AsRef<OsStr> for OsStrimpl AsRef<OsStr> for OsString[src] 
impl AsRef<OsStr> for OsStringimpl AsRef<OsStr> for Path[src] 
impl AsRef<OsStr> for Pathimpl AsRef<OsStr> for PathBuf[src] 
impl AsRef<OsStr> for PathBufimpl AsRef<OsStr> for String[src] 
impl AsRef<OsStr> for Stringimpl AsRef<Path> for str[src] 
impl AsRef<Path> for strimpl AsRef<Path> for OsStr[src] 
impl AsRef<Path> for OsStrimpl AsRef<Path> for OsString[src] 
impl AsRef<Path> for OsStringimpl AsRef<Path> for Path[src] 
impl AsRef<Path> for Pathimpl AsRef<Path> for PathBuf[src] 
impl AsRef<Path> for PathBufimpl AsRef<Path> for String[src] 
impl AsRef<Path> for Stringimpl<'a> AsRef<OsStr> for Component<'a>[src] 
impl<'a> AsRef<OsStr> for Component<'a>impl<'a> AsRef<OsStr> for Components<'a>[src] 
impl<'a> AsRef<OsStr> for Components<'a>impl<'a> AsRef<OsStr> for std::path::Iter<'a>[src] 
impl<'a> AsRef<OsStr> for std::path::Iter<'a>impl<'a> AsRef<Path> for Cow<'a, OsStr>[src] 
impl<'a> AsRef<Path> for Cow<'a, OsStr>impl<'a> AsRef<Path> for Component<'a>[src] 
impl<'a> AsRef<Path> for Component<'a>impl<'a> AsRef<Path> for Components<'a>[src] 
impl<'a> AsRef<Path> for Components<'a>impl<'a> AsRef<Path> for std::path::Iter<'a>[src] 
impl<'a> AsRef<Path> for std::path::Iter<'a>impl<'a, T> AsRef<[T]> for std::slice::Iter<'a, T>[src] 
impl<'a, T> AsRef<[T]> for std::slice::Iter<'a, T>impl<'a, T> AsRef<T> for Cow<'a, T> where
    T: ToOwned + ?Sized, [src] 
impl<'a, T> AsRef<T> for Cow<'a, T> where
    T: ToOwned + ?Sized, impl<'a, T, U> AsRef<U> for &'a T where
    T: AsRef<U> + ?Sized,
    U: ?Sized, [src] 
impl<'a, T, U> AsRef<U> for &'a T where
    T: AsRef<U> + ?Sized,
    U: ?Sized, impl<'a, T, U> AsRef<U> for &'a mut T where
    T: AsRef<U> + ?Sized,
    U: ?Sized, [src] 
impl<'a, T, U> AsRef<U> for &'a mut T where
    T: AsRef<U> + ?Sized,
    U: ?Sized, impl<T> AsRef<[T]> for [T; 0][src] 
impl<T> AsRef<[T]> for [T; 0]impl<T> AsRef<[T]> for [T; 1][src] 
impl<T> AsRef<[T]> for [T; 1]impl<T> AsRef<[T]> for [T; 2][src] 
impl<T> AsRef<[T]> for [T; 2]impl<T> AsRef<[T]> for [T; 3][src] 
impl<T> AsRef<[T]> for [T; 3]impl<T> AsRef<[T]> for [T; 4][src] 
impl<T> AsRef<[T]> for [T; 4]impl<T> AsRef<[T]> for [T; 5][src] 
impl<T> AsRef<[T]> for [T; 5]impl<T> AsRef<[T]> for [T; 6][src] 
impl<T> AsRef<[T]> for [T; 6]impl<T> AsRef<[T]> for [T; 7][src] 
impl<T> AsRef<[T]> for [T; 7]impl<T> AsRef<[T]> for [T; 8][src] 
impl<T> AsRef<[T]> for [T; 8]impl<T> AsRef<[T]> for [T; 9][src] 
impl<T> AsRef<[T]> for [T; 9]impl<T> AsRef<[T]> for [T; 10][src] 
impl<T> AsRef<[T]> for [T; 10]impl<T> AsRef<[T]> for [T; 11][src] 
impl<T> AsRef<[T]> for [T; 11]impl<T> AsRef<[T]> for [T; 12][src] 
impl<T> AsRef<[T]> for [T; 12]impl<T> AsRef<[T]> for [T; 13][src] 
impl<T> AsRef<[T]> for [T; 13]impl<T> AsRef<[T]> for [T; 14][src] 
impl<T> AsRef<[T]> for [T; 14]impl<T> AsRef<[T]> for [T; 15][src] 
impl<T> AsRef<[T]> for [T; 15]impl<T> AsRef<[T]> for [T; 16][src] 
impl<T> AsRef<[T]> for [T; 16]impl<T> AsRef<[T]> for [T; 17][src] 
impl<T> AsRef<[T]> for [T; 17]impl<T> AsRef<[T]> for [T; 18][src] 
impl<T> AsRef<[T]> for [T; 18]impl<T> AsRef<[T]> for [T; 19][src] 
impl<T> AsRef<[T]> for [T; 19]impl<T> AsRef<[T]> for [T; 20][src] 
impl<T> AsRef<[T]> for [T; 20]impl<T> AsRef<[T]> for [T; 21][src] 
impl<T> AsRef<[T]> for [T; 21]impl<T> AsRef<[T]> for [T; 22][src] 
impl<T> AsRef<[T]> for [T; 22]impl<T> AsRef<[T]> for [T; 23][src] 
impl<T> AsRef<[T]> for [T; 23]impl<T> AsRef<[T]> for [T; 24][src] 
impl<T> AsRef<[T]> for [T; 24]impl<T> AsRef<[T]> for [T; 25][src] 
impl<T> AsRef<[T]> for [T; 25]impl<T> AsRef<[T]> for [T; 26][src] 
impl<T> AsRef<[T]> for [T; 26]impl<T> AsRef<[T]> for [T; 27][src] 
impl<T> AsRef<[T]> for [T; 27]impl<T> AsRef<[T]> for [T; 28][src] 
impl<T> AsRef<[T]> for [T; 28]impl<T> AsRef<[T]> for [T; 29][src] 
impl<T> AsRef<[T]> for [T; 29]impl<T> AsRef<[T]> for [T; 30][src] 
impl<T> AsRef<[T]> for [T; 30]impl<T> AsRef<[T]> for [T; 31][src] 
impl<T> AsRef<[T]> for [T; 31]impl<T> AsRef<[T]> for [T; 32][src] 
impl<T> AsRef<[T]> for [T; 32]impl<T> AsRef<[T]> for [T][src] 
impl<T> AsRef<[T]> for [T]impl<T> AsRef<[T]> for Vec<T>[src] 
impl<T> AsRef<[T]> for Vec<T>impl<T> AsRef<Vec<T>> for Vec<T>[src] 
impl<T> AsRef<Vec<T>> for Vec<T>impl<T> AsRef<T> for Box<T> where
    T: ?Sized, [src] 
impl<T> AsRef<T> for Box<T> where
    T: ?Sized, impl<T> AsRef<T> for Rc<T> where
    T: ?Sized, [src] 
impl<T> AsRef<T> for Rc<T> where
    T: ?Sized, impl<T> AsRef<T> for Arc<T> where
    T: ?Sized, [src] 
impl<T> AsRef<T> for Arc<T> where
    T: ?Sized,