konst::maybe_uninit

Struct UNINIT

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pub struct UNINIT<T>(/* private fields */);
Expand description

Generic constant for an uninitialized MaybeUninit<T>. Usable to safely construct a [MaybeUninit<T>; LEN] when T is non-Copy.

As of Rust 1.65.0, [MaybeUninit::uninit(); LEN] is not valid for non-Copy types, but [CONST; LEN] does work, like in the example below.

§Example

use konst::maybe_uninit::{self as mu, UNINIT};

use std::mem::{self, MaybeUninit};

// Intentionally doesn't implement `Copy`
#[derive(Debug, PartialEq, Eq, Clone)]
struct NonCopy(u8);

const INITS: [NonCopy; 5] = {
    let mut uninits = [UNINIT::<NonCopy>::V; 5];
    konst::for_range!{i in 0..5=>
        uninits[i] = MaybeUninit::new(NonCopy(i as u8 * 3));
    }
    unsafe{ mu::array_assume_init(uninits) }
};

assert_eq!(INITS, [NonCopy(0), NonCopy(3), NonCopy(6), NonCopy(9), NonCopy(12)]);

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impl<T> UNINIT<T>

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pub const V: MaybeUninit<T> = _

The value that this constructs.

Auto Trait Implementations§

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impl<T> Freeze for UNINIT<T>

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impl<T> RefUnwindSafe for UNINIT<T>
where T: RefUnwindSafe,

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impl<T> Send for UNINIT<T>
where T: Send,

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impl<T> Sync for UNINIT<T>
where T: Sync,

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impl<T> Unpin for UNINIT<T>
where T: Unpin,

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impl<T> UnwindSafe for UNINIT<T>
where T: UnwindSafe,

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, W> HasTypeWitness<W> for T
where W: MakeTypeWitness<Arg = T>, T: ?Sized,

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const WITNESS: W = W::MAKE

A constant of the type witness
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impl<T> Identity for T
where T: ?Sized,

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const TYPE_EQ: TypeEq<T, <T as Identity>::Type> = TypeEq::NEW

Proof that Self is the same type as Self::Type, provides methods for casting between Self and Self::Type.
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type Type = T

The same type as Self, used to emulate type equality bounds (T == U) with associated type equality constraints (T: Identity<Type = U>).
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.