“C++ as a "Live at Head" Language”
summary
Google runs a monorepo with ~250M lines of C++ and 12,000 active developers and claims C++ can be maintained by building from head rather than pinning releases. The plan centers on Live at Head plus automated edits (millions of edits, clang-tidy/clang tooling), shipping Abseil with a five‑year compatibility window, and providing migration tools for API changes so maintainers can update users. Rules: don’t rely on ADL or internal/ABI details, expect namespace additions, and require unit tests and well‑behaved code for safe automated refactors.
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chapters (11)
- 0:00Introduction by Chandler Carruth
- 2:58Motivation for Live at Head
- 8:01Software engineering vs programming
- 15:02Dependency management challenges
- 27:59Solving diamond dependencies
- 39:26Introducing Abseil libraries
- 43:42Abseil compatibility guidelines
- 53:58Abseil features and design
- 1:01:20Why C++ suits Live at Head
- 1:04:30Call to action for Live at Head
- 1:08:33Q&A session
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