Landing: 9b076412e6ae

Project / Subsystem

gcc / libstdc++

Date

2026-04-29

Author

Tomasz Kamiński

Commit

9b076412e6aecac70504607b5181483ef3e6d754

Source

github

Perf win

Yes

Breaking

No

All attributes

project
gcc
subsystem
libstdc++
patch_id
commit_hash
9b076412e6aecac70504607b5181483ef3e6d754
source_type
github
headline
Libstdc++: Format all contiguous ranges using span
tldr
Libstdc++ now formats all contiguous ranges as spans, enabling non-locking formatter optimization.
author
Tomasz Kamiński
outcome
committed
performance_win
true
breaking_change
false
series_id
series_parts
[]
tags
  • libstdc++
  • formatting
  • ranges
  • optimization
discussion_id_link
bugzilla_pr
date
2026-04-29T00:00:00.000Z

Libstdc++ now formats all contiguous ranges as a span of possibly-const qualified _Tp. This change enables the _M_format<const span<T>> specialization, which is already used by formatter specializations for ranges. By using raw pointers to iterate during formatting, no stdio lock is taken, enabling enable_nonlocking_formatter_optimization for all contiguous ranges.