CppCon 2026

Working with C++ code can be difficult, and it's made even more difficult when the code isn't your own. Everyone agrees that documentation is necessary when sharing a library. But, as a user of a library, the documentation may not help when you want to know the current state of your program. If you're a veteran C++ programmer then you may easily find your way around memory readouts, putting print statements in exactly the right spots, or reading "between the lines" of the documentation. Some of us are not very experienced, or we aren't able to recompile the code with print statements, or the documentation may not help with the problem.

Hopefully, the author had written a GDB extension to pretty-print their data types. But odds are, they didn't. As library writers, or as people writing classes for others to use and reuse, we can and should be writing debugger visualizers. We can empower our users by lowering the barrier to using the library successfully. Let's make our libraries more accessible. Software is about more than just the source code.

This talk will help you make the most of GDB extensions. After briefly discussing how to get started with GDB assuming zero prior knowledge, we will discuss how to write a GDB pretty-printer, how to set up your system to use the pretty-printer, how to embed it into your compiled binary, and how to distribute it with auto-loading scripts. By the end of the talk, the user will not only know the basics of writing a simple "to_string()", but will also understand how to effectively display containers and how to implement custom debugger-side user-facing extension methods. Let's get excited about debuggers!