Implement Option::contains, Result::contains and Result::contains_err

This increases consistency with other common data structures.
This commit is contained in:
Simon Ochsenreither 2019-07-04 01:38:22 +02:00
parent 088b987307
commit 6f76da494b
2 changed files with 78 additions and 0 deletions

View File

@ -208,6 +208,32 @@ impl<T> Option<T> {
!self.is_some()
}
/// Returns `true` if the option is a [`Some`] value containing the given value.
///
/// # Examples
///
/// ```
/// #![feature(option_result_contains)]
///
/// let x: Option<u32> = Some(2);
/// assert_eq!(x.contains(&2), true);
///
/// let x: Option<u32> = Some(3);
/// assert_eq!(x.contains(&2), false);
///
/// let x: Option<u32> = None;
/// assert_eq!(x.contains(&2), false);
/// ```
#[must_use]
#[inline]
#[unstable(feature = "option_result_contains", issue = "62358")]
pub fn contains<U>(&self, x: &U) -> bool where U: PartialEq<T> {
match self {
Some(y) => x == y,
None => false,
}
}
/////////////////////////////////////////////////////////////////////////
// Adapter for working with references
/////////////////////////////////////////////////////////////////////////

View File

@ -309,6 +309,58 @@ impl<T, E> Result<T, E> {
!self.is_ok()
}
/// Returns `true` if the result is an [`Ok`] value containing the given value.
///
/// # Examples
///
/// ```
/// #![feature(option_result_contains)]
///
/// let x: Result<u32, &str> = Ok(2);
/// assert_eq!(x.contains(&2), true);
///
/// let x: Result<u32, &str> = Ok(3);
/// assert_eq!(x.contains(&2), false);
///
/// let x: Result<u32, &str> = Err("Some error message");
/// assert_eq!(x.contains(&2), false);
/// ```
#[must_use]
#[inline]
#[unstable(feature = "option_result_contains", issue = "62358")]
pub fn contains<U>(&self, x: &U) -> bool where U: PartialEq<T> {
match self {
Ok(y) => x == y,
Err(_) => false
}
}
/// Returns `true` if the result is an [`Err`] value containing the given value.
///
/// # Examples
///
/// ```
/// #![feature(result_contains_err)]
///
/// let x: Result<u32, &str> = Ok(2);
/// assert_eq!(x.contains_err(&"Some error message"), false);
///
/// let x: Result<u32, &str> = Err("Some error message");
/// assert_eq!(x.contains_err(&"Some error message"), true);
///
/// let x: Result<u32, &str> = Err("Some other error message");
/// assert_eq!(x.contains_err(&"Some error message"), false);
/// ```
#[must_use]
#[inline]
#[unstable(feature = "result_contains_err", issue = "62358")]
pub fn contains_err<F>(&self, f: &F) -> bool where F: PartialEq<E> {
match self {
Ok(_) => false,
Err(e) => f == e
}
}
/////////////////////////////////////////////////////////////////////////
// Adapter for each variant
/////////////////////////////////////////////////////////////////////////