syntax_data: {"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // "coercion cast" i.e. using a coercion or is a no-op.
context_before:         // `ExprKind::Use` happens when a `hir::ExprKind::Cast` is a
context_after:         // This is important so that `N as usize as usize` doesn't unify with `N as usize`. (untested)