STL

# Microsoft's C++ Standard Library

This is the official repository for Microsoft's implementation of the C++ Standard Library (also known as the STL),
which ships as part of the MSVC toolset and the Visual Studio IDE.

* Our [Changelog][] tracks which updates to this repository appear in each VS release.
* Our [Status Chart][] displays our overall progress over time.
* Join our [Discord server][].
* [![CI Status Badge][STL-CI-badge]][STL-CI-link] (STL-CI build status)
* [![ASan CI Status Badge][STL-ASan-CI-badge]][STL-ASan-CI-link] (STL-ASan-CI build status)

# What This Repo Is Useful For

If you're a programmer who just wants to use the STL, you **don't** need this repo. Simply install the Visual Studio IDE
and select the "Desktop development with C++" workload.

If you want to participate in the STL's development, welcome! You can report issues, comment on pull requests, and learn
about what we're working on. You can also submit pull requests to fix bugs or add features: see [CONTRIBUTING.md][] for
more information.

Finally, you can take our code and use it in other apps and libraries (according to the terms of our license, like
everything else).

# GitHub Migration Status

We're in the process of moving all of our work on the STL to GitHub. Current status:

* Code: **Done.** Our source code is available under the Apache License v2.0 with LLVM Exception. (See
[LICENSE.txt][] and [NOTICE.txt][] for more information.)

* Build System: **In progress.** We're working on a CMake build system, which is currently capable of building one
flavor of the STL (native desktop). We need to extend this to build all of the flavors required for the MSVC toolset
(e.g. `/clr`, `/clr:pure`, OneCore, Spectre). Until that's done, we're keeping our legacy build system around in the
`stl/msbuild` subdirectory. (We're keeping those files in this repo, even though they're unusable outside of Microsoft,
because they need to be updated whenever source files are added/renamed/deleted. We'll delete the legacy machinery as
soon as possible.)

* Tests: **In progress.** We rely on three test suites: std, tr1, and [libcxx][]. We've partially ported std and tr1,
and fully ported libcxx to run under [lit][] using the various configurations/compilers we test internally.

* Continuous Integration: **In progress.** We've set up Azure Pipelines to validate changes to the repository.
Currently, it builds the STL for x64, x86, ARM64, and ARM64EC. Also, it strictly verifies that all of our
files have been formatted with [clang-format][] and follow our other whitespace conventions.

* Contribution Guidelines: **Coming soon.** Working on the STL's code involves following many rules. We have codebase
conventions, Standard requirements, Microsoft-specific requirements, binary compatibility (ABI) requirements, and more.
We're eager to begin accepting features and fixes from the community, but in addition to setting up a CI system, we need
to