Libc++ 23.0.0 (In-Progress) Release Notes

Written by the Libc++ Team

Warning

These are in-progress notes for the upcoming libc++ 23.0.0 release. Release notes for previous releases can be found on the Download Page.

Introduction

This document contains the release notes for the libc++ C++ Standard Library, part of the LLVM Compiler Infrastructure, release 23.0.0. Here we describe the status of libc++ in some detail, including major improvements from the previous release and new feature work. For the general LLVM release notes, see the LLVM documentation. All LLVM releases may be downloaded from the LLVM releases web site.

For more information about libc++, please see the Libc++ Web Site or the LLVM Web Site.

Note that if you are reading this file from a Git checkout or the main Libc++ web page, this document applies to the next release, not the current one. To see the release notes for a specific release, please see the releases page.

What’s New in Libc++ 23.0.0?

Implemented Papers

Improvements and New Features

Deprecations and Removals

Potentially breaking changes

Announcements About Future Releases

ABI Affecting Changes

  • std::allocator is trivially default constructible since LLVM 22. The behaviour can be reverted by defining _LIBCPP_DEPRECATED_ABI_NON_TRIVIAL_ALLOCATOR. Please inform the libc++ team if you need this flag, since it will be removed in LLVM 24 if there is no evidence that it’s required.

  • bitset::operator[] returns bool since LLVM 22, making libc++ conforming. The behaviour can be reverted by defining _LIBCPP_DEPRECATED_ABI_BITSET_CONST_SUBSCRIPT_RETURN_REF. Please inform the libc++ team if you need this flag, since it will be removed in LLVM 24 if there is no evidence that it’s required.

Build System Changes