Libc++ 8.0.0 (In-Progress) Release Notes

Written by the Libc++ Team


These are in-progress notes for the upcoming libc++ 8 release. Release notes for previous releases can be found on the Download Page.


This document contains the release notes for the libc++ C++ Standard Library, part of the LLVM Compiler Infrastructure, release 8.0.0. 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 Subversion 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++ 8.0.0?

API Changes

  • Building libc++ for Mac OSX 10.6 is not supported anymore.
  • Starting with LLVM 8.0.0, users that wish to link together translation units built with different versions of libc++’s headers into the same final linked image MUST define the _LIBCPP_HIDE_FROM_ABI_PER_TU macro to 1 when building those translation units. Not defining _LIBCPP_HIDE_FROM_ABI_PER_TU to 1 and linking translation units built with different versions of libc++’s headers together may lead to ODR violations and ABI issues. On the flipside, code size improvements should be expected for everyone not defining the macro.