AVLTreeMap strategy Auto discards const

[pdziepak]

Member functions CompareKeyNode and CompareNodes of AVLTreeMapStrategy::Auto attempt to implicitly discard const qualifier.

[bonefish]

Wouldn't it be better to fix the strategy members instead. Or have you tried that and there's a problem with it?

[pdziepak]

This patch fixes that particular problem in probably the best way. However, it looks like there are still const correctness problems (or at least const_casts worth removing) in AVLTreeMap implementation. At least, now, everything that NFSv4 client needs from it works correctly.

[bonefish]

Thanks for the update, Pawel. In the NodeStrategy comment, the const in the return value of GetKey() is superfluous, since it isn't a reference. Please note that the return value isn't a reference by intent, since in some cases the key isn't stored as a sub-object in the node object, but has to be computed (if it can, the node strategy is allowed to return a const reference though, since that is assignment compatible).

I also wonder why the GetKey() version with a non-const Node* parameter would be needed at all. I would say a const version would suffice.

And finally I don't think the new GetValue() version is ever called. AFAICT the only caller is AVLTreeMap::_GetValue(Node* node), which has a non-const node anyway.

[pdziepak]

Thank you for feedback. Now, this patch is much simpler.

[bonefish]

Thanks! Applied in hrev44273.