Elemental functions cannot be pointed to by procedure pointers - function

Question

I'm trying to use a procedure pointer (new feature in Fortran 2003) to point to an elemental function but it does not work. I really need the function to be ELEMENTAL and need a pointer to it. Is it truly impossible to point to an elemental function in Fortran?
module elemfunc
implicit none
contains
elemental function fun111(x) result(y)
real*8, intent(in) :: x
real*8 :: y
y = x**2+1
end function fun111
end module elemfunc
program testptr
use elemfunc
implicit none
interface
elemental function func (z)
real*8 :: func
real*8, intent (in) :: z
end function func
end interface
procedure (func), pointer :: ptr
ptr => fun111
print *, ptr( (/1.0d0,2.0d0/) )
end program testptr
Error message:
main.f90:12.7:ptr=>fun111
1
Nonintrinstic elemental procedure pointer 'func111' is invalid in procedure pointer assignment at (1)

Answer 1

In paragraph 7.4.2 Pointer Assignment of the fortran 2003 standard it is explicitly stated that this is not allowed:
C728 (R742) The proc-target shall not be a nonintrinsic elemental procedure
(This constraint is still there in the fortran 2008 standard, so it hasn't been relaxed.)

Answer 2

I had this exact same issue and did not even realize it was an issue until I compiled with gfortran. Unfortunately, it is also forbidden to have dummy procedure arguments to elemental procedures. It is, however, still possible to achieve the functionality you want, though it is a bit kludgy.
What you can legally do is have an elemental function call a pure function. Depending on your needs, the elemental function can be type bound or not.
Option one
Put the procedure pointer and function inside a module:
module A
implicit none
procedure(func_IF), pointer :: ptr => null()
abstract interface
pure function func_IF(x)
real, intent(in) :: x
real :: func_IF
end function
end interface
contains
! Non type bound elemental
elemental function myfun1(x) result(r)
real, intent(in) :: x
real :: r
if(associated(ptr)) r = ptr(x)
end function
end module
Option two
Put both pointer and function inside a derived type:
module B
implicit none
type :: foo
procedure(func_IF), nopass, pointer :: ptr => null()
contains
procedure, pass :: myfun2
end type
abstract interface
pure function func_IF(x)
real, intent(in) :: x
real :: func_IF
end function
end interface
contains
! Type bound elemental
elemental function myfun2(this, x) result(r)
class(foo), intent(in) :: this
real, intent(in) :: x
real :: r
if(associated(this%ptr)) r = this%ptr(x)
end function
end module
A small test program:
program main
use A
use B
implicit none
type(foo) :: myfoo
myfoo%ptr => bar
ptr => bar
print*, myfun1([10., 20.])
print*, myfoo%myfun2([10., 20.])
contains
! Demo pure function with interface func_IF
pure function bar(x)
real, intent(in) :: x
real :: bar
bar = x**2
end function
end