[PATCH] D25771: [change-namespace] shorten namespace qualifier based on UsingDecl and UsingDirectiveDecl.

[Haojian Wu via cfe-commits]

hokein added a comment.

One more comment, otherwise looks good.



================
Comment at: change-namespace/ChangeNamespace.cpp:275
+       (DiffOldNsSplitted.empty() ? "-" : DiffOldNsSplitted.front()))
+          .str();
+  auto IsInMovedNs =
----------------
Using an invalid name `-` is not an elegant solution to me. Is it possible to avoid it? 
Maybe we can explicitly specify `IsVisibleInNewNs` using the code like:

```
Optional<ast_matchers::internal::Matcher<NamedDecl>> IsVisibleInNewNs = IsInMovedNs;
if (!DiffOldNsSplitted.empty() )  {
  std::string Prefix = ... 
  IsVisibleInNewNs = anyOf(*IsVisibleInNewNs, unless(hasAncestor(namespaceDecl(hasName(Prefix));
}
```


https://reviews.llvm.org/D25771