THIS DOESN'T WORK: undefined reference to `int asd<int, 0>(int*)'

#include <type_traits>
#include <iostream>
using namespace std;

template <typename T, typename enable_if< is_array<T>::value, int >::type =0 > int asd(T*){
    cout<<"This is for arrays"<<endl;
    return 0;
}

template <typename T, typename enable_if< !is_array<T>::value, int >::type =0 > int asd(T*){
    cout<<"This is for NON arrays"<<endl;
    return 0;
}

int main() {
	int dummy=3;
	int (*voided)(void*)=(int (*)(void*))asd<decltype(dummy)>;
	voided(&dummy);
}






THIS DOES:

#include <type_traits>
#include <iostream>
using namespace std;

template <typename T, typename enable_if< is_array<T>::value, int >::type =0 > int asd(T*){
    cout<<"This is for arrays"<<endl;
    return 0;
}

template <typename T, typename enable_if< !is_array<T>::value, int >::type =0 > int asd(T*){
    cout<<"This is for NON arrays"<<endl;
    return 0;
}

int main() {
	int dummy=3;
	int (*temp)(decltype(dummy)*)=asd<decltype(dummy)>;
	int (*voided)(void*)=(int (*)(void*))temp;
	voided(&dummy);
}