Don’t blindly prefer emplace_back to push_back

I’ve personally never encountered the particular misunderstanding the author dispels here, but I’m sure the post is written from bitter experience. On the one hand, I shouldn’t be that surprised: Unfortunately, programming in C++ is really brutal for people who would rather learn by example than by carefully reading documentation.

But on the other hand, my instinctive reaction is: Come on, is this really something that confuses people? emplace_back is all about constructing something in-place, which is exactly the opposite of moving it there! How can any professional programmer be 180 degrees wrong about the purpose of a function they use regularly?

What I want to say here is that C++ is really hard, and that there are a million subtle things that one simply has to look up instead of making educated guesses. I don’t think people appreciate this difficulty enough.

I learn C++ by example by using the VSCode debugger. I prefer it over gdb with tui. It won’t go all the way (e.g. educational/smallish projects only that are single threaded) but by that time a programmer has seen some wonky things happening that they can hypothesize about. In my case:

- dangling pointers

- integer under/overflow

- macro expansion (not via debugger but VSCode helps with this)

- double values not being the same when you expect them to be the same

- Seeing if something is copied or moved [1]

[1] Not sure if this is actually true. But I think it can be true by simply stepping inside the function like emplace_back

If you're using Linux, run your test programs under valgrind. It'll help you immensely to find memory issues.