[Boost-users] [BGL] adding an edge without modifying a graph?!

Subject: [Boost-users] [BGL] adding an edge without modifying a graph?!
From: Ireneusz Szcześniak (irek.szczesniak_at_[hidden])
Date: 2015-10-15 09:10:13

Hi,

The subject sounds crazy, I know.  But I need to add reverse edges so 
I can run a max-flow algorithm on my graph, and I would not like to 
modify the input graph.

I can make a copy of the graph, modify it all right, run a max-flow 
algorithm, and discard the modified graph, but that would be inefficient.

So I wonder whether someone could share some trick on how to do that, 
if this is possible.  I was hoping to use boost::subgraph: create a 
root graph, create its subgraph, and then add reverse edges only to 
the root graph.  Unfortunately, these edges also popped up in the 
subgraph.

Thanks & best,
Irek