syntax_data: {"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// with a placeholder region `'%a`, the variable `'_` would just be
context_before: /// `for<'a> Foo<'_>: 'a`, and you instantiate your bound region `'a`
context_after: /// instantiated to the placeholder region `'%a`, which is wrong because