| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| class(bidir_node), | intent(inout) | :: | this | |||
| logical, | intent(in), | optional | :: | deallocate_old | Whether to deallocate (rather than just nullify) any existing
p nodes in the chain. Defaults to |
Unsets the pointer to the previous node in the chain, severing it.
By default, the pointer is only nullified. This may result in a
memory leak. Optionally, by setting deallocate_old=.true., the
previous node (and all previous nodes it points to) can be
deallocated. This may result in a segfault if another part of the
program tries to access the former previous node.
subroutine unset_prev(this, deallocate_old)
!* Author: Chris MacMackin
! Date: February 2016
!
! Unsets the pointer to the previous node in the chain, severing it.
! By default, the pointer is only nullified. This may result in a
! memory leak. Optionally, by setting `deallocate_old=.true.`, the
! previous node (and all previous nodes it points to) can be
! deallocated. This may result in a segfault if another part of the
! program tries to access the former previous node.
!
class(bidir_node), intent(inout) :: this
logical, optional, intent(in) :: deallocate_old
!! Whether to deallocate (rather than just nullify) any existing
!! p nodes in the chain. Defaults to `.false.`.
if (.not. this%has_prev()) return
if (present(deallocate_old)) then
if (deallocate_old) then
call this%prev%unset_prev(.true.)
deallocate(this%prev)
return
end if
end if
nullify(this%prev)
end subroutine unset_prev