P2641R4 `is_within_lifetime()`: Checking If A Union Alternative Is Active
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compiler
cxx26
- Dominant language
- C++
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Description
WG21-P2641R4 is_within_lifetime(): Checking If A Union Alternative Is Active
WG21-P3450R1 Extend is_within_lifetime()
Feature-test macro (in WG21-N5046; note that the original papers depicted a different macro name than what was ultimately merged by cplusplus/draft#6348 and cplusplus/draft#8881):
#define __cpp_lib_is_within_lifetime 202603L
Note: We are not yet accepting PRs for C++26 features.
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 reading WG21-P2641R4 and WG21-P3450R1, then compare their requested feature with the stated feature-test macro. The issue names no implementation files or tests, and says PRs for C++26 features are not yet accepted, so completion criteria and a suitable entry point are not currently provided.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- devtools
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 15/100