[boost] Has anyone thought about adding a general case subset class?

Subject: [boost] Has anyone thought about adding a general case subset class?
From: jrmarsha (jrmarsha_at_[hidden])
Date: 2018-11-04 01:54:15

I've got a lot working with my madlib version of graph, but I've been 
thinking over the elegant ways to add the subgraph feature in BGL.  It 
occurred to me that this can be phrased as a more general problem as 
container subsets.  And while we're at that, then we can add objects or 
operators for set operations like inner join, left join, and outer join.

Can I get some thoughts?