foo.cc: In member function ‘void BigIntArray::sort()’:
foo.cc:43:12: error: no matching function for call to ‘BigIntArray::sort(std::vector<BigInt>::iterator, std::vector<BigInt>::iterator)’
   43 |        sort(arr.begin(), arr.end());
      |        ~~~~^~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:41:10: note: candidate: ‘void BigIntArray::sort()’
   41 |     void sort()
      |          ^~~~
foo.cc:41:10: note:   candidate expects 0 arguments, 2 provided