Create CSR graph from GraphViz file

[Johan Oudinet <johan.oudinet@…>]

From the 3 graph classes available so far in the BGL (adjacency_list, adjacency_matrix and compressed_sparse_row_graph), CSR is the only one that cannot be created with read_graphviz, which requires a MutableGraph).

However, it will be great to have such a possibility, even by using a different function.

[Jeremiah Willcock]

That would be a nice feature to have; I have started on it, but the implementation fails when internal property maps are put into the dynamic_properties object passed to the Graphviz reader. There does not appear to be a good way to fix that problem without changing (with a performance penalty) the way internal property maps are returned from a CSR graph. Although I commented out the test case, you should now be able to pass a CSR graph to read_graphviz as long as you use something like a vector_property_map for properties rather than either internal properties or iterator_property_map.

[Jeremiah Willcock]

(In [77222]) Made Graphviz reading into CSR graphs work for external properties only; refs #5442