How do I pass a function as parameter?

Question

What is the fastest and shortest way to pass a function as parameter of another function without using other libraries other than the std one in just one line?

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Answer 1

Try "pointers to member functions" if your function is a member of any class.

Answer 2

You are looking at several options.

1. function pointers, the C style way
2. std::function which is part of C++ TR1 and C++11
3. use functors and std::ptr_fun to adapt your function

The syntax you are showing is only going to work with C++11. Earlier C++ versions don't offer the possibility to define an anonymous function.

Answer 3

C++11 provides anonymous functions:

forloop(3, []{ std::cout "Hi!"; });

Example:

#include <iostream>
#include <functional>

 void forloop(int times, std::function<void()> f) {
     for(int i = 0; i < times; i++) {
         f();
     }
 }

int main() {
    forloop(3, [] () { std::cout << "Hello world"; });
}