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Move Option::unwrap_or_default

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David Tolnay 2021-12-30 10:34:35 -08:00
parent b7a0ab18f6
commit bbcf09f2fb
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1 changed files with 39 additions and 41 deletions
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80
library/core/src/option.rs
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@ -810,6 +810,45 @@ impl<T> Option<T> {
}
}
/// Returns the contained [`Some`] value or a default.
///
/// Consumes the `self` argument then, if [`Some`], returns the contained
/// value, otherwise if [`None`], returns the [default value] for that
/// type.
///
/// # Examples
///
/// Converts a string to an integer, turning poorly-formed strings
/// into 0 (the default value for integers). [`parse`] converts
/// a string to any other type that implements [`FromStr`], returning
/// [`None`] on error.
///
/// ```
/// let good_year_from_input = "1909";
/// let bad_year_from_input = "190blarg";
/// let good_year = good_year_from_input.parse().ok().unwrap_or_default();
/// let bad_year = bad_year_from_input.parse().ok().unwrap_or_default();
///
/// assert_eq!(1909, good_year);
/// assert_eq!(0, bad_year);
/// ```
///
/// [default value]: Default::default
/// [`parse`]: str::parse
/// [`FromStr`]: crate::str::FromStr
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_option_ext", issue = "91930")]
pub const fn unwrap_or_default(self) -> T
where
T: ~const Default,
{
match self {
Some(x) => x,
None => Default::default(),
}
}
/// Returns the contained [`Some`] value, consuming the `self` value,
/// without checking that the value is not [`None`].
///
@ -1685,47 +1724,6 @@ impl<T: Clone> Option<&mut T> {
}
}
impl<T: Default> Option<T> {
/// Returns the contained [`Some`] value or a default.
///
/// Consumes the `self` argument then, if [`Some`], returns the contained
/// value, otherwise if [`None`], returns the [default value] for that
/// type.
///
/// # Examples
///
/// Converts a string to an integer, turning poorly-formed strings
/// into 0 (the default value for integers). [`parse`] converts
/// a string to any other type that implements [`FromStr`], returning
/// [`None`] on error.
///
/// ```
/// let good_year_from_input = "1909";
/// let bad_year_from_input = "190blarg";
/// let good_year = good_year_from_input.parse().ok().unwrap_or_default();
/// let bad_year = bad_year_from_input.parse().ok().unwrap_or_default();
///
/// assert_eq!(1909, good_year);
/// assert_eq!(0, bad_year);
/// ```
///
/// [default value]: Default::default
/// [`parse`]: str::parse
/// [`FromStr`]: crate::str::FromStr
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_option_ext", issue = "91930")]
pub const fn unwrap_or_default(self) -> T
where
T: ~const Default,
{
match self {
Some(x) => x,
None => Default::default(),
}
}
}
impl<T: Deref> Option<T> {
/// Converts from `Option<T>` (or `&Option<T>`) to `Option<&T::Target>`.
///