foo.cc:3:14: error: variable or field 'playing' declared void
    3 | void playing(p1,p2)
      |              ^~
foo.cc:3:14: error: 'p1' was not declared in this scope
foo.cc:3:17: error: 'p2' was not declared in this scope
    3 | void playing(p1,p2)
      |                 ^~
foo.cc: In function 'int main()':
foo.cc:18:3: error: 'playing' was not declared in this scope
   18 |   playing(b,c);
      |   ^~~~~~~

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