Pass 2d array to subroutine as 1d argument fortran - arrays

Question

I want to pass a 2d array to a subroutine and treat this array as a 1d argument. I tried to pass it in this way: subroutine(array(1,:)). This works if I define the arrays explicitly. However, if the arrays are allocatable, I get the following error: Actual argument for 'array' must be ALLOCATABLE
How can I make this work?
Here is some short sample code, which gives the error above:
program array
implicit none
integer,dimension(:,:),allocatable::i
allocate(i(2,2))
i(1,1)=1
call array_method(i(1,:))
contains
subroutine array_method(i)
implicit none
integer,allocatable,dimension(:),intent(in)::i
write(*,*) i(1)
end subroutine array_method
end program array
If I change code to explicitly defined arrays, like below, it works. However, I want to do it with allocatable arrays.
program array
implicit none
integer,dimension(2,2)::i
i(1,1)=1
call array_method(i(1,:))
contains
subroutine array_method(i)
implicit none
integer,dimension(2),intent(in)::i
write(*,*) i(1)
end subroutine array_method
end program array
If I change the argument array in the subroutine to allocatable and leave the passed argument in the main program as explicitly defined array (for example (2,2)), I still get the same error.

Answer 1

In the subroutine array_method (first one), you give the allocatable attribute to the dummy argument. This requires that the actual argument also has that attribute.
However, the actual argument is i(1,:) which is not allocatable, even though i itself is.
Now, depending on what you want to do in the first case, the dummy argument doesn't need to have the allocatable attribute. Unless you want to change the allocation status (which you can't given intent(in)), or use the "real" bounds of i, you can do without it.