gnu g++-13 can't find wchar.h in mac OS, but xcode tools is installed?

Question

In file included from /usr/local/Cellar/gcc/13.2.0/include/c++/13/bits/postypes.h:40,
                 from /usr/local/Cellar/gcc/13.2.0/include/c++/13/iosfwd:42,
                 from /usr/local/Cellar/gcc/13.2.0/include/c++/13/ios:40,
                 from /usr/local/Cellar/gcc/13.2.0/include/c++/13/ostream:40,
                 from /usr/local/Cellar/gcc/13.2.0/include/c++/13/iostream:41,
                 from 1_1.cpp:1:
/usr/local/Cellar/gcc/13.2.0/include/c++/13/cwchar:44:10: fatal error: wchar.h: No such file or directory
   44 | #include <wchar.h>
      |          ^~~~~~~~~
compilation terminated.

gnu g++-13 can't find wchar.h in mac OS, but xcode tools is installed? When I try to compile the most simple code in c++ with iostream g++ drops it. I tried to reinstall gcc. Also, I tried to write in terminal this: xcode-select --install