从函数指针作为模板参数进行类型推导

Question

I am new to template and have a bit of problem using them. I am posting the code below which I am not able to code for. Need help in how to do this piece

I need someething like a function pointer being passed as a template argument to the tester class and the TClass instance being passed as the parameter to the constructor. In the constructor the function pointer will be used to bind the testFunc to a member variable of the tester class which is a function pointer. Then while the tester class is destroyed the testFunc will be called. No able to resolve the type deduction for the template

#include <iostream>

using namespace std;

template< class TClass, TClass::*fptr>
class tester
{

    public:
        tester(TClass & testObj, ...) //... refer to the arguments of the test function which is binded
        {
            //bind the function to member fptr variable
        }

        ~tester()
        {
            //call the function which was binded here
        }

    private:
        (TClass::*fp)(...) fp_t;
};

class Specimen
{
    public:
        int testFunc(int a, float b)
        {
            //do something
            return 0;
        }
}

int main()
{
    typedef int (Specimen::*fptr)(int,float);
    Specimen sObj;

    {
        tester<fptr> myTestObj(sObj, 10 , 1.1);
    }
    return 0
}

Answer 1

using C++11 std::bind :

#include <functional>
#include <iostream>

class Specimen
{
public:
  int testFunc(int a, float b)
  {
    std::cout << "a=" << a << " b=" << b <<std::endl;
    return 0;
  }
};

int main()
{
  Specimen sObj;
  auto test = std::bind(&Specimen::testFunc, &sObj, 10, 1.1);
  test();
}

Check the documentation .

Answer 2

I mixed std::function and std::bind to get close to your problem:

template<typename F>
class tester
{
    function<F> func;
public:
    template <typename H, typename... Args>
    tester(H &&f, Args&&... args) : func(bind(f, args...))
    {
    }

    ~tester()
    {
        func();
    }
};

class Specimen
{
public:
    int testFunc(int a, float b)
    {
        return a + b;
    }
};

int main()
{
    Specimen sObj;

    tester<int()> myTestObj(&Specimen::testFunc, &sObj, 10 , 1.1);
}

Live code