[PATCH] D103491: [ADT] Move DenseMapInfo for ArrayRef/StringRef into respective headers (NFC)

[Chris Lattner via Phabricator via cfe-commits]

lattner added inline comments.


================
Comment at: llvm/include/llvm/ADT/ArrayRef.h:595-600
+      if (RHS.data() == getEmptyKey().data())
+        return LHS.data() == getEmptyKey().data();
+      if (RHS.data() == getTombstoneKey().data())
+        return LHS.data() == getTombstoneKey().data();
+      return LHS == RHS;
+    }
----------------
craig.topper wrote:
> lattner wrote:
> > I'm pretty sure this method can just be "return LHS == RHS;"  The tombstone/empty comparisons should work without special cases.
> Doesn't operator== on ArrayRef compare the elements of the arrays? So wouldn't that dereference the invalid pointers used by tombstone/empty?
Yes, implemented in terms of std::equal.  However, both of these cases have zero elements, so the "pointer" is never dereferenced.


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  https://reviews.llvm.org/D103491/new/

https://reviews.llvm.org/D103491