Here’s my version. I’m afraid it isn’t what you are after, but it seems to fit the criteria: http://coliru.stacked-crooked.com/a/bf551030554da947

Why not. I’m not expecting one particular answer, the point of the challenge is also to search together how to write good code, with everyone expressing their opinion on that particular question. So if you can do better than for_each then no problem!

Thanks. How about not using std::for_each?

In theory it’s not the only thing you can modify. For instance you could decide to somehow wrap the collection itself, I guess. The goal is to have a piece of code that reads: apply the obvious choice for f, on every object in the collection, in the most expressive way. Hope that’s clearer, and don’t hesitate if you have more questions.