1=========================================
2Libc++ 13.0.0 (In-Progress) Release Notes
3=========================================
4
5.. contents::
6   :local:
7   :depth: 2
8
9Written by the `Libc++ Team <https://libcxx.llvm.org>`_
10
11.. warning::
12
13   These are in-progress notes for the upcoming libc++ 13 release.
14   Release notes for previous releases can be found on
15   `the Download Page <https://releases.llvm.org/download.html>`_.
16
17Introduction
18============
19
20This document contains the release notes for the libc++ C++ Standard Library,
21part of the LLVM Compiler Infrastructure, release 13.0.0. Here we describe the
22status of libc++ in some detail, including major improvements from the previous
23release and new feature work. For the general LLVM release notes, see `the LLVM
24documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM releases may
25be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
26
27For more information about libc++, please see the `Libc++ Web Site
28<https://libcxx.llvm.org>`_ or the `LLVM Web Site <https://llvm.org>`_.
29
30Note that if you are reading this file from a Git checkout or the
31main Libc++ web page, this document applies to the *next* release, not
32the current one. To see the release notes for a specific release, please
33see the `releases page <https://llvm.org/releases/>`_.
34
35What's New in Libc++ 13.0.0?
36============================
37
38New Features
39------------
40
41- ...
42
43API Changes
44-----------
45
46- There has been several changes in the tuple constructors provided by libc++.
47  Those changes were made as part of an effort to regularize libc++'s tuple
48  implementation, which contained several subtle bugs due to these extensions.
49  If you notice a build breakage when initializing a tuple, make sure you
50  properly initialize all the tuple elements - this is probably the culprit.
51
52  In particular, the extension allowing tuples to be constructed from fewer
53  elements than the number of elements in the tuple (in which case the remaining
54  elements would be default-constructed) has been removed. See https://godbolt.org/z/sqozjd.
55
56  Also, the extension allowing a tuple to be constructed from an array has been
57  removed. See https://godbolt.org/z/5esqbW.
58