Optimize Mapper::findBy variants: reserve + emplace_back + optional move #2510
Merged
an-tao merged 1 commit intodrogonframework:masterfrom May 6, 2026
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
No public API change
What's changed:
ret.reserve(r.size())before the row loop.Result::size()isnoexceptand O(1), so this is essentially free and eliminatesemplace_back(row)instead ofpush_back(T(row))as a tiny optimizationprom->set_value(std::move(ret))infindFutureBy.retis a non-const, so withoutstd::movethe whole vector was being copy-constructed into the promiseTest plan
Existing ORM tests still pass