Private methods vs Lambda in C++

Question

My question refers to:

Using a lambda expression versus a private method

Now that lambda functors are part of C++, they could be used to unclutter a class' interface. How does lambda use vs private method use compare in C++? Do there exist better alternatives to unclutter class interfaces?

Answer 1

Although lambdas can definitely replace some private member functions, thinking of them as means to uncluttering the interface of a class is taking too narrow a view of both lambdas and private member functions.

Private member functions (and functions in general) are the basic units of code reuse. They let you write a piece of logic once, and then hide it behind the name of the function.

Although lambdas can replace a private member function in certain context, they could replace an object of which that function is a member along with it, which is a whole lot more. Due to lambda's ability to capture the context around them, you get a way of creating code blocks that take not only your object with it, but also the state of your local variables. Before lambdas you needed to create a special class for that; lambdas let you create such classes on the fly, for much better readability.