newbie question about dictionnary ?

[Sophie Alléon]

Hi,

CONTEXT
I do numerical simulation for which I have to process mesh. A mesh is made
of
triangle which are made of points.
I want from this information to create edges and build triangle from edges
rather
than from points.

PROBLEM
An edge is shared by possibly more than one triangle.

ALGORITHM

have a triangle class  (made of 3 edges)
have an edge   class   (made of 2 points and embeding a triangle list (those
connected to the edge)

for each triangle construct its edges but I have to check if the edge
already exists

for doing this I thought the dictionary was excellent but the key is a
string while I want it
to be the 2 points forming the edge ? How to do it ?

Have you a better idea ?

Thanks

Guillaume