foo.cc:5:9: error: 'node' was not declared in this scope
    5 | int cmp(node l,node r){
      |         ^~~~
foo.cc:5:16: error: 'node' was not declared in this scope
    5 | int cmp(node l,node r){
      |                ^~~~
foo.cc:5:22: error: expression list treated as compound expression in initializer [-fpermissive]
    5 | int cmp(node l,node r){
      |                      ^

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