syntax_data: {"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // it, then move the folded value back into `unique`. Should
context_before:         // Semantically move the contained type out from `unique`, fold
context_after:         // folding fail, `ManuallyDrop` ensures that the "moved-out"