CONTRIBUTING.md - third_party/github/abseil/abseil-cpp - Git at Google

 # How to Contribute to Abseil

 We'd love to accept your patches and contributions to this project. There are
 just a few small guidelines you need to follow.

 NOTE: If you are new to GitHub, please start by reading [Pull Request
 howto](https://help.github.com/articles/about-pull-requests/)

 ## Contributor License Agreement

 Contributions to this project must be accompanied by a Contributor License
 Agreement. You (or your employer) retain the copyright to your contribution,
 this simply gives us permission to use and redistribute your contributions as
 part of the project. Head over to <https://cla.developers.google.com/> to see
 your current agreements on file or to sign a new one.

 You generally only need to submit a CLA once, so if you've already submitted one
 (even if it was for a different project), you probably don't need to do it
 again.

 ## Contribution Guidelines

 Potential contributors sometimes ask us if the Abseil project is the appropriate
 home for their utility library code or for specific functions implementing
 missing portions of the standard. Often, the answer to this question is "no".
 We’d like to articulate our thinking on this issue so that our choices can be
 understood by everyone and so that contributors can have a better intuition
 about whether Abseil might be interested in adopting a new library.

 ### Priorities

 Although our mission is to augment the C++ standard library, our goal is not to
 provide a full forward-compatible implementation of the latest standard. For us
 to consider a library for inclusion in Abseil, it is not enough that a library
 is useful. We generally choose to release a library when it meets at least one
 of the following criteria:

 *   **Widespread usage** - Using our internal codebase to help gauge usage, most
     of the libraries we've released have tens of thousands of users.
 *   **Anticipated widespread usage** - Pre-adoption of some standard-compliant
     APIs may not have broad adoption initially but can be expected to pick up
     usage when it replaces legacy APIs. `absl::from_chars`, for example,
     replaces existing code that converts strings to numbers and will therefore
     likely see usage growth.
 *   **High impact** - APIs that provide a key solution to a specific problem,
     such as `absl::FixedArray`, have higher impact than usage numbers may signal
     and are released because of their importance.
 *   **Direct support for a library that falls under one of the above** - When we
     want access to a smaller library as an implementation detail for a
     higher-priority library we plan to release, we may release it, as we did
     with portions of `absl/meta/type_traits.h`. One consequence of this is that
     the presence of a library in Abseil does not necessarily mean that other
     similar libraries would be a high priority.

 ### API Freeze Consequences

 Via the
 [Abseil Compatibility Guidelines](https://abseil.io/about/compatibility), we
 have promised a large degree of API stability. In particular, we will not make
 backward-incompatible changes to released APIs without also shipping a tool or
 process that can upgrade our users' code. We are not yet at the point of easily
 releasing such tools. Therefore, at this time, shipping a library establishes an
 API contract which is borderline unchangeable. (We can add new functionality,
 but we cannot easily change existing behavior.) This constraint forces us to
 very carefully review all APIs that we ship.


 ## Coding Style

 To keep the source consistent, readable, diffable and easy to merge, we use a
 fairly rigid coding style, as defined by the
 [google-styleguide](https://github.com/google/styleguide) project. All patches
 will be expected to conform to the style outlined
 [here](https://google.github.io/styleguide/cppguide.html).

 ## Guidelines for Pull Requests

 *   If you are a Googler, it is required that you send us a Piper CL instead of
     using the GitHub pull-request process. The code propagation process will
     deliver the change to GitHub.

 *   Create **small PRs** that are narrowly focused on **addressing a single
     concern**. We often receive PRs that are trying to fix several things at a
     time, but if only one fix is considered acceptable, nothing gets merged and
     both author's & review's time is wasted. Create more PRs to address
     different concerns and everyone will be happy.

 *   For speculative changes, consider opening an [Abseil
     issue](https://github.com/abseil/abseil-cpp/issues) and discussing it first.
     If you are suggesting a behavioral or API change, consider starting with an
     [Abseil proposal template](ABSEIL_ISSUE_TEMPLATE.md).

 *   Provide a good **PR description** as a record of **what** change is being
     made and **why** it was made. Link to a GitHub issue if it exists.

 *   Don't fix code style and formatting unless you are already changing that
     line to address an issue. Formatting of modified lines may be done using
    `git clang-format`. PRs with irrelevant changes won't be merged. If
     you do want to fix formatting or style, do that in a separate PR.

 *   Unless your PR is trivial, you should expect there will be reviewer comments
     that you'll need to address before merging. We expect you to be reasonably
     responsive to those comments, otherwise the PR will be closed after 2-3
     weeks of inactivity.

 *   Maintain **clean commit history** and use **meaningful commit messages**.
     PRs with messy commit history are difficult to review and won't be merged.
     Use `rebase -i upstream/master` to curate your commit history and/or to
     bring in latest changes from master (but avoid rebasing in the middle of a
     code review).

 *   Keep your PR up to date with upstream/master (if there are merge conflicts,
     we can't really merge your change).

 *   **All tests need to be passing** before your change can be merged. We
     recommend you **run tests locally** (see below)

 *   Exceptions to the rules can be made if there's a compelling reason for doing
     so. That is - the rules are here to serve us, not the other way around, and
     the rules need to be serving their intended purpose to be valuable.

 *   All submissions, including submissions by project members, require review.

 ## Running Tests

 If you have [Bazel](https://bazel.build/) installed, use `bazel test
 --test_tag_filters="-benchmark" ...` to run the unit tests.

 If you are running the Linux operating system and have
 [Docker](https://www.docker.com/) installed, you can also run the `linux_*.sh`
 scripts under the `ci/`(https://github.com/abseil/abseil-cpp/tree/master/ci)
 directory to test Abseil under a variety of conditions.

 ## Abseil Committers

 The current members of the Abseil engineering team are the only committers at
 present.

 ## Release Process

 Abseil lives at head, where latest-and-greatest code can be found.
	# How to Contribute to Abseil

	We'd love to accept your patches and contributions to this project. There are
	just a few small guidelines you need to follow.

	NOTE: If you are new to GitHub, please start by reading [Pull Request
	howto](https://help.github.com/articles/about-pull-requests/)

	## Contributor License Agreement

	Contributions to this project must be accompanied by a Contributor License
	Agreement. You (or your employer) retain the copyright to your contribution,
	this simply gives us permission to use and redistribute your contributions as
	part of the project. Head over to <https://cla.developers.google.com/> to see
	your current agreements on file or to sign a new one.

	You generally only need to submit a CLA once, so if you've already submitted one
	(even if it was for a different project), you probably don't need to do it
	again.

	## Contribution Guidelines

	Potential contributors sometimes ask us if the Abseil project is the appropriate
	home for their utility library code or for specific functions implementing
	missing portions of the standard. Often, the answer to this question is "no".
	We’d like to articulate our thinking on this issue so that our choices can be
	understood by everyone and so that contributors can have a better intuition
	about whether Abseil might be interested in adopting a new library.

	### Priorities

	Although our mission is to augment the C++ standard library, our goal is not to
	provide a full forward-compatible implementation of the latest standard. For us
	to consider a library for inclusion in Abseil, it is not enough that a library
	is useful. We generally choose to release a library when it meets at least one
	of the following criteria:

	* Widespread usage - Using our internal codebase to help gauge usage, most
	of the libraries we've released have tens of thousands of users.
	* Anticipated widespread usage - Pre-adoption of some standard-compliant
	APIs may not have broad adoption initially but can be expected to pick up
	usage when it replaces legacy APIs. `absl::from_chars`, for example,
	replaces existing code that converts strings to numbers and will therefore
	likely see usage growth.
	* High impact - APIs that provide a key solution to a specific problem,
	such as `absl::FixedArray`, have higher impact than usage numbers may signal
	and are released because of their importance.
	* Direct support for a library that falls under one of the above - When we
	want access to a smaller library as an implementation detail for a
	higher-priority library we plan to release, we may release it, as we did
	with portions of `absl/meta/type_traits.h`. One consequence of this is that
	the presence of a library in Abseil does not necessarily mean that other
	similar libraries would be a high priority.

	### API Freeze Consequences

	Via the
	[Abseil Compatibility Guidelines](https://abseil.io/about/compatibility), we
	have promised a large degree of API stability. In particular, we will not make
	backward-incompatible changes to released APIs without also shipping a tool or
	process that can upgrade our users' code. We are not yet at the point of easily
	releasing such tools. Therefore, at this time, shipping a library establishes an
	API contract which is borderline unchangeable. (We can add new functionality,
	but we cannot easily change existing behavior.) This constraint forces us to
	very carefully review all APIs that we ship.


	## Coding Style

	To keep the source consistent, readable, diffable and easy to merge, we use a
	fairly rigid coding style, as defined by the
	[google-styleguide](https://github.com/google/styleguide) project. All patches
	will be expected to conform to the style outlined
	[here](https://google.github.io/styleguide/cppguide.html).

	## Guidelines for Pull Requests

	* If you are a Googler, it is required that you send us a Piper CL instead of
	using the GitHub pull-request process. The code propagation process will
	deliver the change to GitHub.

	* Create small PRs that are narrowly focused on **addressing a single
	concern**. We often receive PRs that are trying to fix several things at a
	time, but if only one fix is considered acceptable, nothing gets merged and
	both author's & review's time is wasted. Create more PRs to address
	different concerns and everyone will be happy.

	* For speculative changes, consider opening an [Abseil
	issue](https://github.com/abseil/abseil-cpp/issues) and discussing it first.
	If you are suggesting a behavioral or API change, consider starting with an
	[Abseil proposal template](ABSEIL_ISSUE_TEMPLATE.md).

	* Provide a good PR description as a record of what change is being
	made and why it was made. Link to a GitHub issue if it exists.

	* Don't fix code style and formatting unless you are already changing that
	line to address an issue. Formatting of modified lines may be done using
	`git clang-format`. PRs with irrelevant changes won't be merged. If
	you do want to fix formatting or style, do that in a separate PR.

	* Unless your PR is trivial, you should expect there will be reviewer comments
	that you'll need to address before merging. We expect you to be reasonably
	responsive to those comments, otherwise the PR will be closed after 2-3
	weeks of inactivity.

	* Maintain clean commit history and use meaningful commit messages.
	PRs with messy commit history are difficult to review and won't be merged.
	Use `rebase -i upstream/master` to curate your commit history and/or to
	bring in latest changes from master (but avoid rebasing in the middle of a
	code review).

	* Keep your PR up to date with upstream/master (if there are merge conflicts,
	we can't really merge your change).

	* All tests need to be passing before your change can be merged. We
	recommend you run tests locally (see below)

	* Exceptions to the rules can be made if there's a compelling reason for doing
	so. That is - the rules are here to serve us, not the other way around, and
	the rules need to be serving their intended purpose to be valuable.

	* All submissions, including submissions by project members, require review.

	## Running Tests

	If you have [Bazel](https://bazel.build/) installed, use `bazel test
	--test_tag_filters="-benchmark" ...` to run the unit tests.

	If you are running the Linux operating system and have
	[Docker](https://www.docker.com/) installed, you can also run the `linux_*.sh`
	scripts under the `ci/`(https://github.com/abseil/abseil-cpp/tree/master/ci)
	directory to test Abseil under a variety of conditions.

	## Abseil Committers

	The current members of the Abseil engineering team are the only committers at
	present.

	## Release Process

	Abseil lives at head, where latest-and-greatest code can be found.