[PATCH] D138539: Use std::nullopt_t instead of NoneType (NFC)

[Balázs Benics via Phabricator via cfe-commits]

steakhal added a comment.

Hm, it would be easier to use `llvm::StringMap<decltype(std::monostate)>` instead of `std::nullopt_t`, or some adhoc empty struct.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D138539/new/

https://reviews.llvm.org/D138539