"libc++" C++ Standard Library

libc++ is a new implementation of the C++ standard library, targeting C++11.

All of the code in libc++ is dual licensed under the MIT license and the UIUC License (a BSD-like license).

New Documentation Coming Soon!

Looking for documentation on how to use, build and test libc++? If so checkout the new libc++ documentation.

Click here for the new libc++ documentation.

Features and Goals

Why a new C++ Standard Library for C++11?

After its initial introduction, many people have asked "why start a new library instead of contributing to an existing library?" (like Apache's libstdcxx, GNU's libstdc++, STLport, etc). There are many contributing reasons, but some of the major ones are:

Platform Support

libc++ is known to work on the following platforms, using g++-4.2 and clang (lack of C++11 language support disables some functionality). Note that functionality provided by <atomic> is only functional with clang.

Current Status

libc++ is a 100% complete C++11 implementation on Apple's OS X.

LLVM and Clang can self host in C++ and C++11 mode with libc++ on Linux.

libc++ is also a 100% complete C++14 implementation. A list of new features and changes for C++14 can be found here.

A list of features and changes for the next C++ standard, known here as "C++1z" (probably to be C++17) can be found here.

Implementation of the post-c++14 Technical Specifications is in progress. A list of features and the current status of these features can be found here.

Ports to other platforms are underway. Here are recent test results for Windows and Linux.

Build Bots

The latest libc++ build results can be found at the following locations.

Get it and get involved!

First please review our Developer's Policy. The documentation for building and using libc++ can be found below.

Notes and Known Issues

Send discussions to the clang mailing list.

Bug reports and patches

If you think you've found a bug in libc++, please report it using the LLVM Bugzilla. If you're not sure, you can post a message to the cfe-dev mailing list or on IRC. Please include "libc++" in your subject.

If you want to contribute a patch to libc++, the best place for that is Phabricator. Please include [libc++] in the subject and add cfe-commits as a subscriber.

Design Documents