syntax_data: {"ast_node_type":"struct","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// a tuple struct like `struct Foo(u32)`, and `false` otherwise.
context_before:     /// Returns `true` if this `DefId` refers to the implicit constructor for
context_after:     pub fn is_constructor(self, def_id: DefId) -> bool {