Table of Contents

Contributor Checklist
Getting Sources
Submitting Patches
Directory Layout and Source Conventions
Coding Style
Bad Identifiers
By Example
Design Notes

The GNU C++ Library is part of GCC and follows the same development model, so the general rules for contributing to GCC apply. Active contributors are assigned maintainership responsibility, and given write access to the source repository. First-time contributors should follow this procedure:

Contributor Checklist


  • Get and read the relevant sections of the C++ language specification. Copies of the full ISO 14882 standard are available on line via the ISO mirror site for committee members. Non-members, or those who have not paid for the privilege of sitting on the committee and sustained their two meeting commitment for voting rights, may get a copy of the standard from their respective national standards organization. In the USA, this national standards organization is ANSI. (And if you've already registered with them you can buy the standard on-line.)

  • The library working group bugs, and known defects, can be obtained here:

  • Peruse the GNU Coding Standards, and chuckle when you hit the part about Using Languages Other Than C.

  • Be familiar with the extensions that preceded these general GNU rules. These style issues for libstdc++ can be found in Coding Style.

  • And last but certainly not least, read the library-specific information found in Porting and Maintenance.


See the legal prerequisites for all GCC contributions.

Historically, the libstdc++ assignment form added the following question:

Which Belgian comic book character is better, Tintin or Asterix, and why?

While not strictly necessary, humoring the maintainers and answering this question would be appreciated.

Please contact Paolo Carlini at or Jonathan Wakely at if you are confused about the assignment or have general licensing questions. When requesting an assignment form from , please CC the libstdc++ maintainers above so that progress can be monitored.

Submitting Patches

Every patch must have several pieces of information before it can be properly evaluated. Ideally (and to ensure the fastest possible response from the maintainers) it would have all of these pieces:

  • A description of the bug and how your patch fixes this bug. For new features a description of the feature and your implementation.

  • A ChangeLog entry as plain text; see the various ChangeLog files for format and content. If you are using emacs as your editor, simply position the insertion point at the beginning of your change and hit CX-4a to bring up the appropriate ChangeLog entry. See--magic! Similar functionality also exists for vi.

  • A testsuite submission or sample program that will easily and simply show the existing error or test new functionality.

  • The patch itself. If you are accessing the SVN repository use svn update; svn diff NEW; else, use diff -cp OLD NEW ... If your version of diff does not support these options, then get the latest version of GNU diff. The SVN Tricks wiki page has information on customising the output of svn diff.

  • When you have all these pieces, bundle them up in a mail message and send it to [email protected]. All patches and related discussion should be sent to the libstdc++ mailing list. In common with the rest of GCC, patches should also be sent to the gcc-patches mailing list.