Question

In code (just paste and copy)is there a way to avoid repetition/listing of template args(line marked in code):

#include <iostream>

using namespace std;


template<class T,class... V>
struct nullptr_
{
    nullptr_(T& obj,V&... args)
    {
        nullptr_hlp(obj,args...);
    }

    template<class A>
    static void nullptr_hlp(A& a);
    {
        a = nullptr;
    }

    template<class A,class... Vs>
    static void nullptr_hlp(A& a,Vs&... args)
    {
        a = nullptr;
        nullptr_hlp(args...);
    }

};


class X : nullptr_<int*,double*,char*>//IS THERE A WAY TO HAVE JUST nullptr_?
{

    int* a;
    double* b;
    char* c;
    typedef nullptr_<decltype(a),decltype(b),decltype(c)> init_;
public:
    X():init_(a,b,c)
    {

    }

};
int main()
{
   X x;
    return 0;
}

Answer 1

nullptr_<int*,double*,char*> becomes an injected class name within X, so you can refer to it without the argument list:

class X : nullptr_<int*,double*,char*>//can't do away with the list here, unless you want to typedef it
{

    int* a;
    double* b;
    char* c;
    //typedef nullptr_<decltype(a),decltype(b),decltype(c)> init_; //don't really need this
public:
    X():nullptr_(a,b,c) //can be used without the argument list
    {

    }
};