syntax_data: {"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // `Pin { __pointer: &mut { $expr } }` and `Pin { __pointer: &$expr }`.
context_before:             // Make `&pin mut $expr` and `&pin const $expr` into
context_after:             hir::ExprKind::AddrOf(hir::BorrowKind::Pin, mutbl, arg_expr) => match expr_ty.kind() {