The problem with a default warning for signed/unsigned comparison is there are many cases of this in large existing codebases where, although it is not ideal, i

The problem with a default warning for signed/unsigned comparison is there are many cases of this in large existing codebases where, although it is not ideal, it doesn't do any harm. Such cases could constitute a large amount of compiler warning output - obviously just making life difficult for maintainers. Personally I always use -Wextra (the relevant flag for clang) when working on my own code.