foo.cc: In function 'std::ostream operator<<(std::ostream&, myclass&)':
foo.cc:13:9: warning: no return statement in function returning non-void [-Wreturn-type]
   13 |         };
      |         ^
foo.cc: At global scope:
foo.cc:40:1: error: redefinition of 'myclass::myclass(int, int, int, int, int, int)'
   40 | myclass::myclass(int x1=0, int x2=0, int x3=0, int x4=0, int x5=0, int x6=0) :y(x1), m1(x2), d(x3), h(x4), m2(x5), s(x6) {};
      | ^~~~~~~
foo.cc:9:9: note: 'myclass::myclass(int, int, int, int, int, int)' previously defined here
    9 |         myclass(int y, int m1, int d, int h, int m2, int s) {};
      |         ^~~~~~~

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