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Move Result::as_deref

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David Tolnay 2021-12-30 10:23:46 -08:00
parent f8d4ee7c7a
commit eda61d8d8a
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1 changed files with 24 additions and 23 deletions
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47
library/core/src/result.rs
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@ -901,6 +901,30 @@ impl<T, E> Result<T, E> {
self
}
/// Converts from `Result<T, E>` (or `&Result<T, E>`) to `Result<&<T as Deref>::Target, &E>`.
///
/// Coerces the [`Ok`] variant of the original [`Result`] via [`Deref`](crate::ops::Deref)
/// and returns the new [`Result`].
///
/// # Examples
///
/// ```
/// let x: Result<String, u32> = Ok("hello".to_string());
/// let y: Result<&str, &u32> = Ok("hello");
/// assert_eq!(x.as_deref(), y);
///
/// let x: Result<String, u32> = Err(42);
/// let y: Result<&str, &u32> = Err(&42);
/// assert_eq!(x.as_deref(), y);
/// ```
#[stable(feature = "inner_deref", since = "1.47.0")]
pub fn as_deref(&self) -> Result<&T::Target, &E>
where
T: Deref,
{
self.as_ref().map(|t| t.deref())
}
/////////////////////////////////////////////////////////////////////////
// Iterator constructors
/////////////////////////////////////////////////////////////////////////
@ -1508,29 +1532,6 @@ impl<T: Into<!>, E> Result<T, E> {
}
}
impl<T: Deref, E> Result<T, E> {
/// Converts from `Result<T, E>` (or `&Result<T, E>`) to `Result<&<T as Deref>::Target, &E>`.
///
/// Coerces the [`Ok`] variant of the original [`Result`] via [`Deref`](crate::ops::Deref)
/// and returns the new [`Result`].
///
/// # Examples
///
/// ```
/// let x: Result<String, u32> = Ok("hello".to_string());
/// let y: Result<&str, &u32> = Ok("hello");
/// assert_eq!(x.as_deref(), y);
///
/// let x: Result<String, u32> = Err(42);
/// let y: Result<&str, &u32> = Err(&42);
/// assert_eq!(x.as_deref(), y);
/// ```
#[stable(feature = "inner_deref", since = "1.47.0")]
pub fn as_deref(&self) -> Result<&T::Target, &E> {
self.as_ref().map(|t| t.deref())
}
}
impl<T: DerefMut, E> Result<T, E> {
/// Converts from `Result<T, E>` (or `&mut Result<T, E>`) to `Result<&mut <T as DerefMut>::Target, &mut E>`.
///