+Nico since this could be an issue in clang-format

Huh, weird!

clang-format works on a token level, so the template nesting level shouldn't faze it much in theory. And indeed, this still happens if I remove all the template bits:

struct CopyRangeSupplement {
  static void CopyRange(const InT* value_begin,
                        const InT* value_end,
                        T* storage_begin) {
    T* storage = storage_begin;
    for (const InT *value = value_begin; value < value_end;
         ++value, ++storage) {
      TypeOperations::Assign(*storage, *value);
    }
  }
};

Simpler repro:

static void CopyRange() {
  foo* value;
  for (InT *value = value_begin; value < value_end; ++value, ++storage) {
  }
}

If I change the third part of the loop header to not contain a comma operator, it works. So I guess that's what confuses clang-format. But this is still pretty simple code, it's surprising this confuses it.

Still happens at trunk. Filed https://bugs.llvm.org/show_bug.cgi?id=34366

Fixed in upstream r34366. Rolling clang-format is a bit annoying to do -- if this is very important to you, we can do a roll. If it's of medium importance, I think it's time to finally build some infra to make clang-format rolls easier (this will take some time, but should hopefully be doable some time this year).

This is not so urgent, since I can reformat the code again when clang-format is
rolled.

A clang-format with the fix got deployed on Nov 21 2018.