# Extra Clang Tools 6 documentation

## clang-tidy - cert-dcl58-cpp

# cert-dcl58-cpp

Modification of the `std` or `posix` namespace can result in undefined behavior. This check warns for such modifications.

Examples:

    namespace std {
      int x; // May cause undefined behavior.
    }

This check corresponds to the CERT C++ Coding Standard rule DCL58-CPP. Do not modify the standard namespaces.