CODEWITHSUNDEEP
c++
user3747190
user3747190

Reputation: 1707

Passing user defined class as template parameter

I am trying to implement Graph in C++.
I have defined a class Edge that take the node name and weight as 2 parameters.
And a class Graph, When I tried to pass Edge as a template parameter in Graph declaration Graph<int,Edge> g, I got an error.
Can't I pass a class as template parameter. I am new to C++ coding, so please pardon me for any stupidity. Can anyone suggest the correct way to do it?

template<class T1,class T2>
    class Edge{
        T1 d_vertex;
        T2 d_weight;
        public:
        Edge(T1,T2);
        T1 vertex();
        T2 weight();
};
template<class T1,class T2>
Edge<T1,T2>::Edge(T1 v,T2 w):d_vertex(v),d_weight(w){
}
template<class T1,class T2>
T1 Edge<T1,T2>:: vertex(){
        return d_vertex;
}
template<class T1,class T2>
T2 Edge<T1,T2>::weight(){
        return d_weight;
}
template<class T,class T2>
class Graph{
        vector<pair<T, list<T2> > > node;

};

int main()
{
    Graph<int,Edge> g;
}

Upvotes: 1

Views: 756

Answers (1)

Nikos Athanasiou
Nikos Athanasiou

Reputation: 31519

In this instantiation

Graph<int,Edge> g;

Edge is still a class template. That implies that either your Graph class should be like that 

template<class T, template<class,class> class T2>
class Graph{ /**/ };

ie having a template template parameter or you should specify the type of the Edge, eg

Graph<int, Edge<int,int>> g;

Upvotes: 2

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