#include <wheels/type_traits.h++>
#include <iostream>
#include <utility>
 
template <typename Fun,
          wheels::EnableIf<wheels::is_callable<Fun, void(int, int)>> = wheels::_> 
void run(int a, Fun&& f) {
  std::forward<Fun>(f)(a, a);
}
 
 
template <typename Fun,
          wheels::EnableIf<wheels::is_callable<Fun, void(int)>> = _> 
void run(int a, Fun&& f) {
  std::forward<Fun>(f)(a);
}
 
int main() {
  run(34,[] (int i, int j)  { std::cout << i  << j << std::endl; });
}

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