anchor.diff:  ! Provide interfaces and wrappers to hashing procedures that are written in C++.
   
   ! Warning: only working with i0 as a 32-bit or 64-bit integer.
  -
  -use const
   
   implicit none
   
  
positive.code:         !    Hash of f using the MurmurHash2 algorithm.
  
          use, intrinsic:: iso_c_binding
  
          integer(i0) :: hash
          integer(i0), intent(in), target :: f(N)
  
negative.code:         ! Returns:
          !    32-bit hash of data.
          use, intrinsic:: iso_c_binding
          integer(c_int32_t) :: hash
          type(c_ptr), value :: key
          integer(c_int), value :: N
          integer(c_int32_t), value :: seed
      end function MurmurHash2
  end interface
  
  