Ppxlib.Reserved_namespacesSmall module to reserve namespaces in attribute names.
reserve "foo" has two implications:
check_unusedThis is here to insure that the rewriter cohabits well with other rewriter or tools (e.g. merlin) which might leave attribute on the AST.
N.B. the following namespaces are reserved by default: merlin, reason, refmt ns, res, metaocaml, ocamlformat and ppxlib.