A clean way to store a function and its (arbitrary-type, arbitrary-number) arguments

Question

For a library, I\'d like a function to accept another function and its arguments, then store them all for calling later. The arguments must allow for any mixture of types, b

Answer 1

You could use lambda functions to hide the bindings:

#include 

class DelayedCaller : public std::function< void(void) > {
public:
    DelayedCaller(std::function< void(void) > fn)
      : std::function< void(void) >(fn) {}
};

DelayedCaller caller1([]() { myFunc1(123, 45.6); });
DelayedCaller caller2([]() { myFunc2("A string"); });

caller1(); // Calls myFunc1(), with arguments 123 and 45.6
caller2(); // Calls myFunc2(), with argument "A string"

This also gives your library's users more flexibility. They're not limited to a single function call and the functions have access to the original environment they were created in:

int x;

DelayedCaller caller3 = [&x]() {
    if (x == 0)
        DoSomething();
    else
        DoSomethingElse();
};