Explicit Instantiation of Template with Template integer parameter

Question

How do I explicitly instantiate a Template with integer parameter

Example :

foo.h

template<int DIM>
class foo{
public: 
    foo();
};

foo.cpp

#include "foo.h"
template<int DIM>
foo<DIM>::foo(){
    return;
}

main.cpp

#include "foo.h"
int main(){
    foo<1> obj;
    return 0;
}

Here, I get a main.cpp: undefined reference to `foo<1>::foo()'

Typically we use a template class foo in the cpp file. How do we do this in this case.

thanks

EDIT : Solution Similar to the template class foo, we just need to add

template class foo<1>;