Describe the bug

When compiling, it appears this error, which I tried to fix by following the instructions:

"in Cpp2, write 'using the_namespace_name::' to bring all names in the namespace into scope using the '' wildcard (at 'using')"

It is ignored

To Reproduce
Steps to reproduce the behavior:

Just add using namespace std::_; in any file and compile.

Additional context

Add any other context about the problem here.