how to write wrapper for ‘allocate’

by

This can be done via a generic interface block. You have to create procedures for each rank that you want to handle, e.g., memory_1d, memory_2d, … memory_4d. (Obviously a lot of cut & pasting.) Then you write a generic interface block that gives all of these procedures the alternative name memory as a generic procedure name. When you call memory, the compiler distinguishes which memory_Xd should be called based on the rank of the argument. The same for your freem functions.

This is how intrinsic functions such as sin have long worked — you can call sin with a real arguments of various previsions, or with a complex argument, and the compiler figures out with actual sin function to call. In really old FORTRAN you had to use different names for the different sin functions. Now modern Fortran you can setup the same thing with your own routines.

Edit: adding a code example demonstrating the method & syntax:

module double_array_mod

   implicit none

   interface double_array
      module procedure double_vector
      module procedure double_array_2D
   end interface double_array

   private  ! hides items not listed on public statement 
   public :: double_array

contains

   subroutine double_vector (vector)
      integer, dimension (:), intent (inout) :: vector
      vector = 2 * vector
   end subroutine double_vector

   subroutine double_array_2D (array)
      integer, dimension (:,:), intent (inout) :: array
      array = 2 * array
   end subroutine double_array_2D

end module double_array_mod


program demo_user_generic

   use double_array_mod

   implicit none

   integer, dimension (2) :: A = [1, 2]
   integer, dimension (2,2) :: B = reshape ( [11, 12, 13, 14], [2,2] )
   integer :: i

   write (*, '( / "vector before:", / 2(2X, I3) )' )  A
   call double_array (A)
   write (*, '( / "vector after:", / 2(2X, I3) )' )  A

   write (*, '( / "2D array before:" )' )
   do i=1, 2
      write (*, '( 2(2X, I3) )' )  B (i, :)
   end do
   call double_array (B)
   write (*, '( / "2D array after:" )' )
   do i=1, 2
      write (*, '( 2(2X, I3) )' )  B (i, :)
   end do   

   stop
end program demo_user_generic

More Related Contents:

  1. Fortran running error
  2. Fortran: integer*4 vs integer(4) vs integer(kind=4)
  3. Why Segmentation fault is happening in this openmp code?
  4. What is an undefined reference/unresolved external symbol error and how do I fix it in Fortran?
  5. Is There a Better Double-Precision Assignment in Fortran 90?
  6. changing array dimensions in fortran
  7. Why should I use interfaces?
  8. Sending 2D arrays in Fortran with MPI_Gather
  9. Fortran OpenMP program shows no speedup of CPU_TIME()
  10. Where to put `implicit none` in Fortran
  11. Function has no implicit type
  12. Print to standard output from a function defined in an Fortran module
  13. Why is this a function declared inside the module and then used somewhere else in the same module not seen by the linker?
  14. Does Fortran have undefined behavior?
  15. ‘*’ and ‘/’ not recognized on input by a read statement
  16. Reading data file in Fortran with known number of lines but unknown number of entries in each line
  17. What does “real*8” mean?
  18. Line truncated, Syntax error in argument list
  19. Fortran IF statement with numbers/labels rather than another statement
  20. Function in fortran, passing array in, receiving array out
  21. Providing an argument that has not the TARGET attribute to a procedure with a dummy argument that has the TARGET attribute
  22. Fortran OpenMP with subroutines and functions
  23. Difference between intent(out) and intent(inout)
  24. Error: Nonnegative width required in format string at (1)
  25. Fortran intent(inout) versus omitting intent
  26. Fortran array cannot be returned in function: not a DUMMY variable
  27. Is Fortran unable to do the addition between 865398.78 and -865398.78? Why the answer is -0.03?
  28. Passing size as argument VS assuming shape in Fortran procedures
  29. Fortran SAVE statement
  30. MPI_Gather gives seg fault in the most basic code

Leave a Comment