foo.cc:20:4: error: extended character – is not valid in an identifier
   20 |    n––;
      |    ^
foo.cc:20:4: error: extended character – is not valid in an identifier
foo.cc: In function 'int main()':
foo.cc:20:4: error: 'n\U00002013\U00002013' was not declared in this scope
   20 |    n––;
      |    ^~~

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