Question

I have Vertex template in vertex.h. From my graph.h:

20 template<class edgeDecor, class vertexDecor, bool dir>
21 class Vertex;

which I use in my Graph template.

I’ve used the Vertex template successfully throughout my Graph, return pointers to Vertices, etc. Now for the first time I am trying to declare and instantiate a Vertex object, and gcc is telling me that my ‘declarator’ is ‘invalid’. How can this be?

81 template<class edgeDecor, class vertexDecor, bool dir>
82 Graph<edgeDecor,int,dir> Graph<edgeDecor,vertexDecor,dir>::Dijkstra(vertex s, bool print = false) const
83 {
84    /* Construct new Graph with apropriate decorators */
85    Graph<edgeDecor,int,dir> span = new Graph<edgeDecor,int,dir>();
86    span.E.reserve(this->E.size());
87
88    typename Vertex<edgeDecor,int,dir> v = new Vertex(INT_MAX);
89    span.V = new vector<Vertex<edgeDecor,int,dir> >(this->V.size,v);
90 };

And gcc is saying:

graph.h: In member function ‘Graph<edgeDecor, int, dir> Graph<edgeDecor, vertexDecor, dir>::Dijkstra(Vertex<edgeDecor, vertexDecor, dir>, bool) const’:
graph.h:88: error: invalid declarator before ‘v’
graph.h:89: error: ‘v’ was not declared in this scope

I know this is probably another noob question, but I’ll appreciate any help.

Answer 1

Igor is right. As for the following error:

graph.h:88: error: expected type-specifier before ‘Vertex’ 

… you probably need to say:

Vertex<edgeDecor,int,dir> v = new Vertex<edgeDecor,int,dir>(INT_MAX);