main4.cpp: In function 'int main()':
main4.cpp:37:10: error: no match for 'operator==' (operand types are 'cmps2020_student' and 'cmps2020_student')
   37 |    if (a == b)
      |        ~ ^~ ~
      |        |    |
      |        |    cmps2020_student
      |        cmps2020_student