C++11: Perfect Forwarding

This is the ability to wrap a function without creating all combinations constness overloads. Here is an example:

#include

template

void func(T i)

{

  std::cout << i << " ";;

}

template

void wrapper_without_perfect_forwarding(T& i)

{

  func(i);

}

template

void wrapper_with_perfect_forwarding(T&& i)

{

  func(std::forward(i));

}

int main()

{

  int variable = 1;

  wrapper_without_perfect_forwarding(variable);

  // wrapper_without_perfect_forwarding(2); // Error: 'void wrapper_without_perfect_forwarding(T &)':

                                                                                  //                   cannot convert argument 1 from 'int' to 'int &'

  wrapper_with_perfect_forwarding(variable);

  wrapper_with_perfect_forwarding(3);

  return 0;

}

// Output: 1 1 3

Reference: https://oopscenities.net/2014/02/01/c11-perfect-forwarding/