“used without template parameters”

Question

I realize similar questions have been asked before, but I read a couple of those and still don\'t see where I\'m going wrong. When I simply write my class without separating th

Answer 1

You need to let your compiler know that you are implementing a method in template function:

 template<typename T>
 int VisitedSet<T>::getSize() {
    return vec.size();
 }

Answer 2

VisitedSet is a template, not a class, so you can’t use VisitedSet in a nested name specifier such as VisitedSet::getSize(). Just as you specified the declaration of class VisitedSet<T> for all class T, you must specify the definition of VisitedSet<T>::getSize() for all class T:

template<class T>
int VisitedSet<T>::getSize() {
//            ^^^
    return vec.size();
}

The name of a template can, however, be used as though it were a class within a template definition:

template<class T>
struct Example {
    Example* parent;
    T x, y;
};

In this case, Example is short for Example<T>.

Answer 3

You want this:

template <class T>
int VisitedSet<T>::getSize() {
    return vec.size();
}

Answer 4

You have to state the template parameter in the definition as well

template<class T>
int VisitedSet<T>::getSize() {
    return vec.size();
}

otherwise the compiler cannot match it to the declaration. For example, there could be specializations for some parameter types.

Answer 5

Try putting

template <typename T>

above the implementation of VisitedSet::getSize() -- but beware that, in general, templated classes and functions should all be inlined. See the c++ faq here for more information.