This is meant to be a general place to list things that should be done "someday"

ABI Related Tasks
=================
* Explicitly manage and verify symbols exported from the dylib.
* Explore using namespaces for managing symbol visibility.
* Introduce and document ABI versioning/evolution policy.

CXX Runtime Library Tasks
=========================
* Cleanup #ifdef hell in sources files that supports the different ABI libraries.
* Fix that CMake always link to /usr/lib/libc++abi.dylib on OS X.
* Fix selection of ABI symbol list on OS X.
* Have CMake generate linker scripts for libc++.so that it properly links the
  runtime library.
* Look into mirroring libsupc++'s typeinfo vtable layout when libsupc++/libstdc++
  is used as the runtime library.
* Audit libraries that CMake links into libc++. Are they all required?
* Investigate and document interoperability between libc++ and libstdc++ on
  linux. Do this for every supported c++ runtime library.

Atomic Related Tasks
====================
* Support <atomic> in C++03 (needed for internal use).
* Audit use of libatomic builtins in <atomic> with GCC.
* future should use <atomic> for synchronization.
* call_once should use <atomic> for synchronization.
* Audit shared_ptr use of <atomic>

Test Suite Tasks
================
* Get test suite passing in C++03.
* Move all libc++ specific tests from test/std into test/libcxx.
* Improve how LIT handles compiler warnings.
* Improve the quality and portability of the locale test data.

Misc Tasks
==========
* Find all sequences of >2 underscores and eradicate them.
* run clang-tidy on libc++
* Look at test/std/utilities/meta/meta.trans/meta.trans.other/result_of.pass.cpp;
  why are the tests duplicated?
* Document the "conditionally-supported" bits of libc++
* Look at basic_string's move assignment operator, re LWG 2063 and POCMA
* libc++ is missing try_emplace
* Put a static_assert in std::allocator to deny const/volatile types (LWG 2447)
* Investigate the effect of using __decltype instead of __typeof__ to provide
  decltype in C++03. What code could be broken by this change?
* Convert failure tests to use Clang Verify.
* Document support (or lack of) for C++11 libraries in C++03.
* Document supported compilers.