Implement split_off for BTreeMap and BTreeSet (RFC 509) #33947
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src/libcollections/btree/node.rs
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| // Source and destination must have the same height. | ||
| unsafe fn move_edges<K, V>( | ||
| source: Option<*mut BoxedNode<K, V>>, source_offset: usize, |
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I think I'd prefer if this function took pointers not wrapped in Option - it makes more sense intuitively to me that you would check if you have edges to move, and if so, you call move_edges. I could be convinced otherwise though.
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In fact, it might be even nicer to just take a NodeRef - it is easy to figure out where to place the edges.
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Oh no. This is bad commit. |
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@gereeter, fixed |
src/libcollections/btree/map.rs
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This might be slightly nicer as a match on (split_edge.force(), right_node.force()).
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Sans nits, this looks good to me. Thank you, @xosmig! |
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r? @aturon |
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@gereeter, Thanks for review! |
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should I squash it all into one commit? |
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@bors: delegate=gereeter |
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✌️ @gereeter can now approve this pull request |
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Yes, I think that squashed PRs are standard practice, at least for collections changes like this that don't really have separate, logical steps. |
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The Travis failure looks completely unrelated to this PR. @bors r+ |
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📌 Commit e3adad6 has been approved by |
| /// ``` | ||
| #[unstable(feature = "btree_split_off", | ||
| reason = "recently added as part of collections reform 2", | ||
| issue = "19986")] |
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Since the corresponding issue was closed, I think a new tracking issue is needed for {BTreeMap, BTreeSet}::{append, split_off}.
8 participants
Fixes #19986 and refactors common with append methods.
It splits the tree with O(log n) operations and then calculates sizes by traversing the lower one.
CC @gereeter