Re: [boost] GSOC 2010 - BGL Graph Connectives.

Subject: Re: [boost] GSOC 2010 - BGL Graph Connectives.
From: Andrew Sutton (andrew.n.sutton_at_[hidden])
Date: 2010-03-31 15:57:55

>
> 1) Union ( undi, di ) returns an undi graph : I will convert the directed
> graph to undirected by adding arcs. Then, I unite them.
>
> 2) Union ( undi, di ) returns a di graph : I will consider the undirected
> graph as a directed one with two same arcs between vertices.
>

Is there any particular reason you are choosing this behavior? What
particular use cases does this address? It may be acceptable to not define
unions between undirected and directed graphs.

> 1) If the Union_graph 's properties is clearly declared, I will use
> type-casting. Nevertheless, the challenge is to deal with the non-integral
> data type.
>

Type casting is not a viable solution.

> 2) If the Union_graph 's property is undeclared, I will try to integrate
> two properties. In particular, the vertices and edges of graph 1 will still
> keep their own properties; but they will also have graph_2 's properties, in
> which values will be initialized as 0.
>

Properties are never actually "undeclared". There is always a type that
represents the vertex and edge properties of a graph. You will have to look
a little closer at the implementation of the BGL graph data structures in
order to determine an acceptable approach.

Andrew Sutton
andrew.n.sutton_at_[hidden]