Enum rustc_middle::ty::layout::SizeSkeleton

pub enum SizeSkeleton<'tcx> {
    Known(Size),
    Pointer {
        non_zero: bool,
        tail: Ty<'tcx>,
    },
}

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

Known(Size)

Any statically computable Layout.

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.

A potentially-fat pointer.

Implementations

impl<'tcx> SizeSkeleton<'tcx>

pub fn compute(
    ty: Ty<'tcx>,
    tcx: TyCtxt<'tcx>,
    param_env: ParamEnv<'tcx>
) -> Result<SizeSkeleton<'tcx>, LayoutError<'tcx>>

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

Trait Implementations

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

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

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for SizeSkeleton<'tcx>

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

Formats the value using the given formatter.

impl<'tcx> Copy for SizeSkeleton<'tcx>

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
• Pointer: 15 bytes