syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// variance of `Vec<i32>` is `Contravariant.xform(Invariant)`,
context_before:     /// is true for its `i32` argument. In the `*mut T` case, the
context_after:     /// and hence the outermost type is `Invariant` with respect to