btree: merge the implementations of MergeIter

[ssomers]

Also remove the gratuitous Copy bounds. Same benchmark performance.

r? @Mark-Simulacrum

[bors]

☔ The latest upstream changes (presumably #78060) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[ssomers]

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[Mark-Simulacrum]

@bors r+ rollup=never

[bors]

📌 Commit cc87f6ec3cc28a3c2b4c90631a3e9c6c92bad5d2 has been approved by Mark-Simulacrum

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout btree_merge_mergers (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self btree_merge_mergers --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

Auto-merging library/alloc/src/collections/btree/mod.rs
Auto-merging library/alloc/src/collections/btree/map.rs
CONFLICT (content): Merge conflict in library/alloc/src/collections/btree/map.rs
Automatic merge failed; fix conflicts and then commit the result.

[ssomers]

@bors r+ rollup=never

[bors]

@ssomers: 🔑 Insufficient privileges: Not in reviewers

[bors]

@ssomers: 🔑 Insufficient privileges: not in try users

[ssomers]

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[Mark-Simulacrum]

@bors r+ rollup=never

[bors]

📌 Commit 2c5f64f has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit 2c5f64f with merge b6ac411...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing b6ac411 to master...