Function rustc_codegen_ssa::base::unsized_info

pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
    cx: &Cx, 
    source: Ty<'tcx>, 
    target: Ty<'tcx>, 
    old_info: Option<Cx::Value>
) -> Cx::Value

Retrieves the information we are losing (making dynamic) in an unsizing adjustment.

The old_info argument is a bit odd. It is intended for use in an upcast, where the new vtable for an object will be derived from the old one.