Don’t blindly prefer emplace_back to push_back

*when using it incorrectly. The premise of of emplace_back is that you use it for calling the constructor of the object in place. Obviously it won't help you if you call a copy constructor instead. I find this article a bit pointless. Clang's suggestion was spot-on and emplace_back would have (potentially) helped if the suggestion was actually followed correctly.

But okay, maybe it's more obvious when having worked with pre-C++11 code, where you would have killed for something like emplace_back. If you are new to the language and only know modern C++, you probably don't think much about why emplace_back exists in addition to push_back, and why it can be faster.