Passing object of a Templated struct to a member function of another templated class

Question

I have a template class alpha_x give as,

template 
struct alpha_x {
    const T & alpha;
    const Scalar & x;
    alpha_x(const T & a_, const Scalar & x_) : alpha(a_), x(x_) {};
};

I have another class with an overload for operator =

template 
class Scalar{
    ...
    template 
    const Scalar & operator = (alpha_x c);
    ...
}

When we try to define this function,

template 
const Scalar & Scalar::operator = (alpha_x c){
    //do something...
}

Now this gives an error "Too many template parameters in template redeclaration". How do I sort this out?

user_5517378 · Answer

T template parameter is a class Scalar's template parameter. Thus it needs to be specified in a separate template parameter list.

Following would work:

template 
template 
const Scalar & Scalar::operator = (alpha_x c){
    // do something...
}