[PATCH] D23522: [ADT] Change PostOrderIterator to use NodeRef. NFC.

[David Blaikie via llvm-commits]

dblaikie added inline comments.

================
Comment at: include/llvm/ADT/PostOrderIterator.h:122
@@ -123,3 +121,3 @@
       : po_iterator_storage<SetType, ExtStorage>(S) {
-    if (this->insertEdge((NodeType*)nullptr, BB)) {
+    if (this->insertEdge(Optional<NodeRef>(), BB)) {
       VisitStack.push_back(std::make_pair(BB, GT::child_begin(BB)));
----------------
timshen wrote:
> Yeah, the main reason I don't want that is it aggressively generalize the insertEdge's interface.
Not sure I follow - it doesn't really make the interface more permissive (if there were overloads then you'd need some SFINAE to promote the internal template errors out onto the interface to ensure overload resolution did the right thing is the only big wrinkle) - so far as I can see.

Anything that can be implicitly converted to Optional<NodeRef> seems to be what the function is trying to accept.


https://reviews.llvm.org/D23522