Use [[no_unique_address]] after Clang supports it on Windows
Open
Nobody has claimed this yet.
compiler
performance
vNext
- Dominant language
- C++
- Stars
- 11.1k
- Forks
- 1.7k
- Avg merge
- 4d 15h
- Merged PRs (30d)
- 22
Description
VS 2019 16.9 will support [[no_unique_address]]. Clang lists this as supported in Clang 9. However, we suspect that it is not yet supported when Clang targets Windows, because MSVC didn't support it. So, #1363 is commenting out all of our [[no_unique_address]] usage.
- Confirm whether Clang supports
[[no_unique_address]]on Windows. (Clang does not.) - If it does, proceed to the next step, otherwise we should file an LLVM bug requesting such support, then wait for it to be implemented and available in the version of Clang that ships with VS.
- Finally, we should begin using
[[no_unique_address]]for C++20-only code.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reviewing issue #1363 and the linked Clang C++ status information, then verify support for [[no_unique_address]] when Clang targets Windows. Done means the external support question is resolved and the project can determine whether to restore or begin using the attribute in C++20-only code.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- compilers
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100