Landing: 57a8b54cc4d9

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Project / Subsystem

gcc / libstdc++

Date

2026-05-05

Author

Jonathan Wakely

Commit

57a8b54cc4d9d7750d8e98f1df1cbbb1aacfad09

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: libstdc++
patch_id: —
commit_hash: 57a8b54cc4d9d7750d8e98f1df1cbbb1aacfad09
source_type: github
headline: Libstdc++: Simplify std::shared_ptr internals
tldr: The `_Impl` classes inside `_Sp_counted_deleter` and `_Sp_counted_ptr_inplace` are removed, simplifying the internal layout of `std::shared_ptr`.
author: Jonathan Wakely
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • libstdc++
• shared_ptr
• refactoring
• memory management
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/57a8b54cc4d9d7750d8e98f1df1cbbb1aacfad09
date: 2026-05-05T00:00:00.000Z

The _Impl classes inside _Sp_counted_deleter and _Sp_counted_ptr_inplace are removed. This change simplifies the internal layout of std::shared_ptr by flattening these classes now that empty base optimization (EBO) is no longer used, streamlining memory management and potentially improving performance.