syntax_data: {"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: ///     - an meta-sized type (str, slices, trait objects, etc)
context_before: /// For `Sized`, there are only a few options for the types in the constraint:
context_after: ///     - an pointee-sized type (extern types)