Landing: e309e09187c0

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Project / Subsystem

gcc / libstdc++

Date

2026-05-21

Author

Jonathan Wakely

Commit

e309e09187c07589901df1d3913e4def4afb5817

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: libstdc++
patch_id: —
commit_hash: e309e09187c07589901df1d3913e4def4afb5817
source_type: github
headline: Libstdc++: Deprecate std::memory_order::consume
tldr: Deprecates `std::memory_order::consume` in libstdc++ as part of implementing P3475R2.
author: Jonathan Wakely
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • libstdc++
• atomics
• memory_order
• deprecation
• concurrency
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/e309e09187c07589901df1d3913e4def4afb5817
date: 2026-05-21T00:00:00.000Z

As part of implementing P3475R2, this commit deprecates std::memory_order::consume in libstdc++. The memory_order::consume is considered problematic and ineffective in practice. The commit adds deprecation attributes to memory_order::consume, memory_order_consume (in <stdatomic.h>), and kill_dependency. Testsuite adjustments are included to handle the new deprecation warnings.