[PATCH] D23649: [ADT] Change the range-based for loop in DFS to normal loop. NFC.

[David Blaikie via llvm-commits]

dblaikie accepted this revision.
dblaikie added a comment.

Please update the title as well to match the intent (it's not so much about range based for loop as it is about mutating the original iterator).

Up to you if you consider the local reference preferable to directly modifying 'Opt'.


================
Comment at: include/llvm/ADT/DepthFirstIterator.h:110-114
@@ -109,3 +109,7 @@
 
-      for (NodeRef Next : make_range(*Opt, GT::child_end(Node))) {
+      // Notice that we use `auto &It =` here, as opposed to `auto It =` or
+      // range-based for loop, so that VisitStack.back().second actually gets
+      // updated.
+      for (auto &It = *Opt; It != GT::child_end(Node); ++It) {
+        NodeRef Next = *It;
         // Has our next sibling been visited?
----------------
I /think/ it'd be more explicit & probably not need the comment if you wrote it without the reference:

  for (; *Opt != GT::child_end(Node); ++*Opt) {
    NodeRef Next = **Opt;
    ...




https://reviews.llvm.org/D23649