Include What You Use (IWYU)

Purpose

Guide agents through using IWYU to reduce unnecessary #include directives, interpret IWYU reports and mapping files, decide between forward declarations and full includes, and integrate IWYU into CMake builds to reduce compilation cascades in large codebases.

Triggers

• "How do I use include-what-you-use?"
• "How do I reduce my C++ compilation times by fixing includes?"
• "How do I interpret IWYU output?"
• "Should I use a forward declaration or include?"
• "How do I integrate IWYU with CMake?"
• "What is a compilation cascade and how do I avoid it?"

Workflow

1. Install and run IWYU