如何在fortran中正确定义用户自定义复数的算术运算符重载？

module complex_operators
  implicit none

  type :: my_complex
    real :: re
    real :: im
  end type my_complex

  interface operator (+)
    module procedure complex_addition
  end interface operator (+)

  interface operator (-)
    module procedure complex_subtraction
  end interface operator (-)

  interface operator (*)
    module procedure complex_multiplication
  end interface operator (*)

  interface operator (/)
    module procedure complex_division
  end interface operator (/)

contains

  function complex_addition(a, b) result(c)
    type(my_complex), intent(in) :: a, b
    type(my_complex) :: c

    c%re = a%re + b%re
    c%im = a%im + b%im
  end function complex_addition

  function complex_subtraction(a, b) result(c)
    type(my_complex), intent(in) :: a, b
    type(my_complex) :: c

    c%re = a%re - b%re
    c%im = a%im - b%im
  end function complex_subtraction

  function complex_multiplication(a, b) result(c)
    type(my_complex), intent(in) :: a, b
    type(my_complex) :: c

    c%re = a%re * b%re - a%im * b%im
    c%im = a%re * b%im + a%im * b%re
  end function complex_multiplication

  function complex_division(a, b) result(c)
    type(my_complex), intent(in) :: a, b
    type(my_complex) :: c
    real :: denominator

    denominator = b%re**2 + b%im**2
    c%re = (a%re * b%re + a%im * b%im) / denominator
    c%im = (a%im * b%re - a%re * b%im) / denominator
  end function complex_division

end module complex_operators

program test_complex_operators
  use complex_operators
  implicit none

  type(my_complex) :: z1, z2, z3

  z1%re = 1.0
  z1%im = 2.0

  z2%re = 3.0
  z2%im = 4.0

  z3 = z1 + z2
  print *, "Addition: ", z3%re, z3%im

  z3 = z1 - z2
  print *, "Subtraction: ", z3%re, z3%im

  z3 = z1 * z2
  print *, "Multiplication: ", z3%re, z3%im

  z3 = z1 / z2
  print *, "Division: ", z3%re, z3%im

end program test_complex_operators