http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49213
--- Comment #3 from neil.n.carlson at gmail dot com 2011-06-16 20:35:48 UTC --- (In reply to comment #1) > Note: Intrinsic assignments to polymorphic variables are forbidden [...] This was really about the structure constructor; the assignment was just to do something with the value, so the example was poor. Here's a slightly different version that gets to the heart of what I intended: program main type :: S integer :: n end type type(S) :: Sobj type, extends(S) :: S2 integer :: m end type type(S2) :: S2obj type :: T class(S), allocatable :: x end type Sobj = S(1) call pass_it (T(Sobj)) S2obj = S2(1,2) call pass_it (T(S2obj)) contains subroutine pass_it (foo) type(T), intent(in) :: foo end subroutine end program This gives the same errors: call pass_it (T(Sobj)) 1 Error: Can't convert TYPE(s) to CLASS(s) at (1) call pass_it (T(S2obj)) 1 Error: Can't convert TYPE(s2) to CLASS(s) at (1)