Landing: 4598d7fcbde6
Project / Subsystem
gcc / libstdc++
Date
2026-05-21
Author
Jonathan Wakely
Commit
4598d7fcbde6dd87274a91a247134ba3c12be0cd
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- libstdc++
- patch_id
- —
- commit_hash
- 4598d7fcbde6dd87274a91a247134ba3c12be0cd
- source_type
- github
- headline
- Libstdc++: Add missing constraints to vector and deque deduction guides
- tldr
- Adds constraints to `vector` and `deque` deduction guides to ensure they only accept valid allocator types.
- author
- Jonathan Wakely
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • libstdc++
- • vector
- • deque
- • deduction guides
- • allocator
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-21T00:00:00.000Z
This commit fixes missing constraints in the deduction guides for std::vector and std::deque. The deduction guides now require that the deduced type for the allocator argument must qualify as an allocator. This prevents unexpected behavior and ensures that the containers are constructed with valid allocator types. New test cases are added to verify that deduction fails when a non-allocator type is used.