/in/foo.cc: In function 'void add(int&, int, int, int)':
/in/foo.cc:45:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(!p) p = ++len; ++val[p];
  ^~
/in/foo.cc:45:20: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(!p) p = ++len; ++val[p];
                    ^~