Support of copy constructors?

[rongcuid]

I have a graph which I would like to copy and change one aspect of it (e.g. weight function). However, it seems like MetaGraph doesn't have a copy constructor:

MetaGraph(graph)
# UndefKeywordError: keyword argument `label_type` not assigned

It would be great if something like that is added. Or alternatively, provide a way to create different views of the same graph with different properties.

[gdalle]

Can you just use deepcopy?

[Krastanov]

deepcopy is a reasonable workaround, but just wanted to leave this warning here, about deepcopy being discouraged in production-level / library code: JuliaLang/julia#58416 (so we should probably leave this issue open)

[rongcuid]

Accessors.jl works so far, though I am not sure if I should rely on knowing the internal representation of the MetaGraph struct.

[rafaqz]

It's probably good for the graphs ecosystem to commit to ConstructionBase.constructorof always working on graph objects. It will mostly work already as you found with Accessors.jl (that uses it under the hood), but where arguments and type parameters are unusual it may need a method added. ConstructionBase.jl is a small dependency and usually in your deps anyway.