Struct konst::alloc_type::COW_SLICE_NEW

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pub struct COW_SLICE_NEW<'a, T: Clone + 'a>(/* private fields */);
Available on crate feature alloc only.
Expand description

An empty Cow<'_, [T]>. Usable to construct a [Cow<'_, [T]>; N].

As of Rust 1.65.0, [Cow::Borrowed(&[][..]); LEN] is not valid, because Cow<'_, [T]> isn’t copy, but [CONST; LEN] does work, like in the example below.

§Example

use konst::alloc_type::COW_SLICE_NEW;

use std::borrow::Cow;

const SLICES: [Cow<'_, [u64]>; 6] = [COW_SLICE_NEW::<u64>::V; 6];

let mut cows = SLICES;

[3, 5, 8, 13, 21, 34].iter().copied()
    .enumerate()
    .filter(|(i, _)| i % 2 != 0 )
    .for_each(|(i, v)|{
        cows[i].to_mut().push(v)
    });

assert_eq!(cows, [&[][..], &[5], &[], &[13], &[], &[34]])

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impl<'a, T: Clone + 'a> COW_SLICE_NEW<'a, T>

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pub const V: Cow<'a, [T]> = _

The value that this constructs.

Auto Trait Implementations§

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impl<'a, T> Freeze for COW_SLICE_NEW<'a, T>

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impl<'a, T> RefUnwindSafe for COW_SLICE_NEW<'a, T>
where T: RefUnwindSafe,

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impl<'a, T> Send for COW_SLICE_NEW<'a, T>
where T: Send,

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impl<'a, T> Sync for COW_SLICE_NEW<'a, T>
where T: Sync,

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impl<'a, T> Unpin for COW_SLICE_NEW<'a, T>
where T: Unpin,

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impl<'a, T> UnwindSafe for COW_SLICE_NEW<'a, 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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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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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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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.