syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // In order to please the borrow checker, when lowering a pattern
context_before:             PatKind::Binding { mode, var, ref subpattern, .. } => {
context_after:                 // like `x @ subpat` we must establish any bindings in `subpat`