[PATCH] D84048: DR2303: Prefer 'nearer' base classes during template deduction.

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added inline comments.


================
Comment at: clang/lib/Sema/SemaTemplateDeduction.cpp:1281
+             "Base class that isn't a record?");
+      ToVisit.push_back(Base.getType()->getAs<RecordType>());
+    }
----------------
erichkeane wrote:
> rsmith wrote:
> > It would be better to add the class to `Visited` here rather than in the loop below -- that is, only add each class to `ToVisit` once rather than only processing each class once. That would put a tighter upper bound on the size of `ToVisit`.
> I'm perhaps missing something here... Can you clarify your suggestion a bit more?  If we add it to 'Visited' here, it will never get visited in the while-loop below, right?  
The idea would be to remove the `Visited` check in the loops below. We would guarantee that each class is only visited once by only adding it to `ToVisit` once. (As an example, we do the same thing for `Queue` and `Visited` here: https://github.com/llvm/llvm-project/blob/master/clang/lib/Sema/SemaLookup.cpp#L1992)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84048/new/

https://reviews.llvm.org/D84048