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Add MaybeUninit::new #55252

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Merged
merged 1 commit into from
Oct 28, 2018
Merged

Add MaybeUninit::new #55252

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1 change: 1 addition & 0 deletions src/libcore/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,7 @@
#![feature(const_fn)]
#![feature(const_int_ops)]
#![feature(const_fn_union)]
#![feature(const_manually_drop_new)]
#![feature(custom_attribute)]
#![feature(doc_cfg)]
#![feature(doc_spotlight)]
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9 changes: 9 additions & 0 deletions src/libcore/mem.rs
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Expand Up @@ -1021,6 +1021,15 @@ pub union MaybeUninit<T> {
}

impl<T> MaybeUninit<T> {
/// Create a new `MaybeUninit` initialized with the given value.
///
/// Note that dropping a `MaybeUninit` will never call `T`'s drop code.
/// It is your responsibility to make sure `T` gets dropped if it got initialized.
#[unstable(feature = "maybe_uninit", issue = "53491")]
pub const fn new(val: T) -> MaybeUninit<T> {
MaybeUninit { value: ManuallyDrop::new(val) }
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@scottmcm scottmcm Oct 22, 2018 •
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Should this be spelled From::from? (Additionally/instead/never, I don't know.)

Edit: Sorry for spam during the GitHub outage.

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If we do this as From now, then it cannot be const fn for the time being (but hopefully in the future...).

}

/// Create a new `MaybeUninit` in an uninitialized state.
///
/// Note that dropping a `MaybeUninit` will never call `T`'s drop code.
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