Add generic `addNode` and `addEdge` overloads about cxxgraph

[sbaldu]

This being said, the template variadic list is a neat idea.

If you think that it would be a useful addition we could still implement the new method without using the C++20 requires.
I think that we can implement the check on the template parameters by simply using std::enable_if, which is from C++11 so we don't need to update the standard.
What do you think?

[ZigRazor]

In this way, I think is good!

[nrkramer]

I don't think forcing users to upgrade their version of the C++ standard is necessarily a good thing.

Supporting new features from the standard is fine as long as it's hidden in the library - but if it's in the headers it becomes a far more troublesome problem.

Having the maximum amount of backwards compatibility is a good thing. Most library implementers should strive for that.

This being said, the template variadic list is a neat idea.

[nrkramer]

I think we should discuss and consider the possibility of distributing a standard hpp/cpp library, as the drawbacks of header-only are starting to manifest in this library.

[nrkramer]

This SO article goes over some of the basic points: https://softwareengineering.stackexchange.com/questions/305618/are-header-only-libraries-more-efficient

I do think the low administrative costs of a header-only library make it attractive to keep.

[ZigRazor]

I think we should discuss and consider the possibility of distributing a standard hpp/cpp library, as the drawbacks of header-only are starting to manifest in this library.

I think we can open a discussion in discussion section.

[ZigRazor]

I do think the low administrative costs of a header-only library make it attractive to keep.

I Agree with @nrkramer