How do i write a pointer-to-member-function with std::function?

Question

I know how to declare int fn(double) inside of std::function (std::function). I know how to write a pointer-to-member-function (

Answer 1

One of the guidelines in Scott Meyer's Modern C++11 book is to avoid std::bind and always use a lambda closure instead:

struct A{ int fn(double){ return 0; } };

std::function f = [a = A{}](double x) mutable { return a.fn(x); };

The mutable is necessary here, as the capture a might potentially be changed by the function call (since A::fn is non-const).