Are unused includes harmful in C/C++?

Question

What are the negative consequences of unused includes?

I\'m aware they result in increased binary size (or do they?), anything else?

Answer 1

• Increases compilation time (potentially serious issue)
• Pollutes global namespace.
• Potential clash of preprocessor names.
• If unused headers are included from third-party libraries, it may make such libraries unnecessarily maintained as dependencies.