> However, the new version gives extra flexibility for you to move a long-lived object in and out of lists without copying or allocating

You could also do this with the entire node in the case of a generic implementation though, the API just needs to expose the node struct to you and allow you to detach it; but the same is true for this new implementation as well.

In terms of memory, a detached node that embeds the payload struct isn't different from an object with an embedded detached node.

What changes is that now, if you have an object class that you don't want to (or can't) extend to include a list node, you have to wrap it in a container struct that, again, looks the same in memory but now has a node and your object as its members. I'm not sure if this is really much of an improvement at the end of the day.

Also, correct me if I'm wrong (I don't do zig), but shouldn't it be possible to create a list of void elements from the generic implementation and embed its node type inside your object, then proceed from there as if it were the new implementation?