In file included from iostream:39:
In member function 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char; _Traits = std::char_traits<char>]',
    inlined from 'int main()' at foo.cc:23:10:
/nix/store/1x1q5sqa0ilbi8fz7aayk02pjy5g7jhh-gcc-12.3.0/include/c++/12.3.0/ostream:221:25: warning: 'g' may be used uninitialized [-Wmaybe-uninitialized]
  221 |       { return _M_insert(__f); }
      |                ~~~~~~~~~^~~~~
foo.cc: In function 'int main()':
foo.cc:17:16: note: 'g' was declared here
   17 |         double g;
      |                ^

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