Comment by spacechild1

You are absolutely right of course! No idea, why I thought std::function existed before C++11. Mea culpa!

> Furthermore absolutely no one should use std::bind, it's an absolute abomination.

Agree 100%! I almost always use a wrapper lambda.

However, it's worth pointing out that C++20 gave us std::bind_front(), which is really useful if you want to just bind the first N arguments:

    struct Foo {
        void bar(int a, int b, int c);
    };

    Foo foo;

    using Callback = std::function<void(int, int, int)>;

    // with std::bind (ugh):
    using namespace std::placeholders;
    Callback cb1(std::bind(&Foo::bar, &foo, _1, _2, _3));

    // lambda (without perfect forwarding):
    Callback cb2([&foo](auto&&... args) { foo.bar(args...); });

    // lambda (with perfect forwarding):
    Callback cb3([&foo](auto&&... args) { foo.bar(std::forward<decltype(args)>(args)...); });

    // std::bind_front
    Callback cb4(std::bind_front(&Foo::bar, &foo));

I think std::bind_front() is the clear winner here.