Landing: e906bebbf21d
Project / Subsystem
gcc / libstdc++
Date
2026-06-30
Author
Anlai Lu
Commit
e906bebbf21dc50a5c4db9afa358db6e48d4706b
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- libstdc++
- patch_id
- —
- commit_hash
- e906bebbf21dc50a5c4db9afa358db6e48d4706b
- source_type
- github
- headline
- Libstdc++: Use __chrono_write for chrono ostream insertion.
- tldr
- Libstdc++ chrono output now uses a new helper function for improved formatting and buffer management.
- author
- Anlai Lu
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • libstdc++
- • chrono
- • formatting
- • iostream
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-06-30T00:00:00.000Z
The C++ standard library’s chrono formatting for operator<< has been refactored to use a new helper function, __detail::__chrono_write. This function formats chrono objects into a stack buffer using std::format_to_n and then writes the output via __ostream_insert. This change consolidates formatting logic, allows per-type buffer tuning via a _BufSize template parameter, and replaces older methods like std::format, std::vformat, and basic_stringstream for chrono output.