This is missing code after 1.3.1 such as the vf2 aglorithm

[rimmartin]

Hi,

Any interest in the head of lemon library? 1.3.1 is missing lemon/vf2.h

Needing you -std=c++20 changes and the vf2 algorithm

[maliberty]

We currently use c++17 in the OR compile. Can the head compile with that? Is this for something you are adding to OR (otherwise why not use the upstream)?

[rimmartin]

Hi @maliberty , we've been using the HEAD with c++17 since we worked with the lemon team to put in
http://lemon.cs.elte.hu/hg/lemon-main/file/a278d16bd2d0/lemon/vf2.h in 2020. Unfortunately my contact is not longer responding from there otherwise would have asked them to bump to -std=c++20.

I see you have fixed the deprecated allocation in https://github.com/The-OpenROAD-Project/lemon-graph/blob/master/lemon/bits/array_map.h to compile with c++20.

We use vf2 for finding graph symmetry; not sure if is important for other lemon users