}

impl<Dyn: ?Sized> DynMetadata<Dyn> {

/// One of the things that rustc_middle does with this being a lang item is

/// give it `FieldsShape::Primitive`, which means that as far as codegen can

/// tell, it *is* a reference, and thus doesn't have any fields.

/// That means we can't use field access, and have to transmute it instead.

/// When `DynMetadata` appears as the metadata field of a wide pointer, the rustc_middle layout

/// computation does magic and the resulting layout is *not* a `FieldsShape::Aggregate`, instead

/// it is a `FieldsShape::Primitive`. This means that the same type can have different layout

/// depending on whether it appears as the metadata field of a wide pointer or as a stand-alone

/// type, which understandably confuses codegen and leads to ICEs when trying to project to a

/// field of `DynMetadata`. To work around that issue, we use `transmute` instead of using a

/// field projection.

#[inline]

fn vtable_ptr(self) -> *const VTable {

// SAFETY: this layout assumption is hard-coded into the compiler.