pub enum SizeSkeleton<'tcx> {
    Known(Size),
    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

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

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

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

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

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