syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // elaborated, so check if a `Sized` obligation is being elaborated to a
context_before:         // parameter environments, as an optimisation, sizedness supertraits aren't
context_after:         // `MetaSized` obligation and emit it. Candidate assembly and confirmation