[PATCH] D30853: Improve the genericity of `llvm::enumerate()`.

[Zachary Turner via Phabricator via llvm-commits]

zturner added inline comments.


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Comment at: llvm/include/llvm/ADT/STLExtras.h:1024
+          typename std::iterator_traits<IterOfRange<R>>::pointer,
+          typename std::iterator_traits<IterOfRange<R>>::reference> {
+  using result_type = result_pair<R>;
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bryant wrote:
> can iterator_adaptor_base be used for this? it looks like its default template params fit.
I was not able to make this work well.  `iterator_adapter_base` stores a copy of the iterator  While I also want to store a copy of the iterator, I also need to store an index.  And I need both to be part of the iterator's `value_type`.  So if I want to use `iterator_adapter_base`, It becomes wasteful because I store a copy of the iterator twice.  Once in `iterator_adapter_base` and again in the `result` member variable.


https://reviews.llvm.org/D30853