syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// "constrained" when you equate this type with another type. In
context_before:     /// `true` if we only want regions that are known to be
context_after:     /// particular, if you have e.g., `&'a u32` and `&'b u32`, equating