Children of a given impl, grouped into blanket/non-blanket varieties as is done in TraitDef.

A per-trait graph of impls in specialization order. At the moment, this graph forms a tree rooted with the trait itself, with all other nodes representing impls, and parent-child relationships representing specializations.

Information about the most specialized definition of an associated item.


A node in the specialization graph is either an impl or a trait definition; either can serve as a source of item definitions. There is always exactly one trait definition node: the root.

What kind of overlap check are we doing – this exists just for testing and feature-gating purposes.


Walk up the specialization ancestors of a given impl, starting with that impl itself.