#include <iostream>

    template<bool B, typename T>
    std::string doSomething(T t);

    template<>
    std::string doSomething<true>(std::string s) {
      return "true!";
    }

    template<>
    std::string doSomething<false>(int i) {
      return "false!";
    }


    int main() {
      std::string foo {"foo"};

      auto s1 = doSomething<true>(foo);
      auto s2 = doSomething<false>(42);

      std::cout << s1 << ", " << s2 << std::endl;
  
      return 0;
    }