SizeSkeleton

Enum SizeSkeleton 

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pub enum SizeSkeleton<'tcx> {
    Known(Size, Option<Align>),
    Generic(Const<'tcx>),
    Pointer {
        non_zero: bool,
        tail: Ty<'tcx>,
    },
}
Expand description

Type size “skeleton”, i.e., the only information determining a type’s size. While this is conservative, (aside from constant sizes, only pointers, newtypes thereof and null pointer optimized enums are allowed), it is enough to statically check common use cases of transmute.

Variants§

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Known(Size, Option<Align>)

Any statically computable Layout. Alignment can be None if unknown.

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Generic(Const<'tcx>)

This is a generic const expression (i.e. N * 2), which may contain some parameters. It must be of type usize, and represents the size of a type in bytes. It is not required to be evaluatable to a concrete value, but can be used to check that another SizeSkeleton is of equal size.

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Pointer

A potentially-wide pointer.

Fields

§non_zero: bool

If true, this pointer is never null.

§tail: Ty<'tcx>

The type which determines the unsized metadata, if any, of this pointer. Either a type parameter or a projection depending on one, with regions erased.

Implementations§

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impl<'tcx> SizeSkeleton<'tcx>

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pub fn compute( ty: Ty<'tcx>, tcx: TyCtxt<'tcx>, typing_env: TypingEnv<'tcx>, ) -> Result<SizeSkeleton<'tcx>, &'tcx LayoutError<'tcx>>

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pub fn same_size(self, other: SizeSkeleton<'tcx>) -> bool

Trait Implementations§

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impl<'tcx> Clone for SizeSkeleton<'tcx>

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fn clone(&self) -> SizeSkeleton<'tcx>

Returns a duplicate of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl<'tcx> Debug for SizeSkeleton<'tcx>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl<'tcx> Copy for SizeSkeleton<'tcx>

Auto Trait Implementations§

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impl<'tcx> DynSend for SizeSkeleton<'tcx>

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impl<'tcx> DynSync for SizeSkeleton<'tcx>

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impl<'tcx> Freeze for SizeSkeleton<'tcx>

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impl<'tcx> !RefUnwindSafe for SizeSkeleton<'tcx>

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impl<'tcx> Send for SizeSkeleton<'tcx>

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impl<'tcx> Sync for SizeSkeleton<'tcx>

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impl<'tcx> Unpin for SizeSkeleton<'tcx>

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impl<'tcx> !UnwindSafe for SizeSkeleton<'tcx>

Blanket Implementations§

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impl<T> Aligned for T

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const ALIGN: Alignment

Alignment of Self.
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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<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

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fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut T

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fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx mut [T]

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impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

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fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut T

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fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx mut [T]

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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> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T, R> CollectAndApply<T, R> for T

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fn collect_and_apply<I, F>(iter: I, f: F) -> R
where I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

Equivalent to f(&iter.collect::<Vec<_>>()).

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type Output = R

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impl<T> DynClone for T
where T: Clone,

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fn __clone_box(&self, _: Private) -> *mut ()

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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> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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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> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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impl<P> IntoQueryParam<P> for P

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impl<T> MaybeResult<T> for T

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type Error = !

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fn from(_: Result<T, <T as MaybeResult<T>>::Error>) -> T

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fn to_result(self) -> Result<T, <T as MaybeResult<T>>::Error>

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impl<T> Pointable for T

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const ALIGN: usize

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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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.
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impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

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fn upcast(self, interner: I) -> U

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impl<I, T> UpcastFrom<I, T> for T

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fn upcast_from(from: T, _tcx: I) -> T

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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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impl<Tcx, T> Value<Tcx> for T
where Tcx: DepContext,

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default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T

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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<T> ErasedDestructor for T
where T: 'static,

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes

Size for each variant:

  • Known: 15 bytes
  • Generic: 15 bytes
  • Pointer: 15 bytes