Fortran Object Oriented Programming Abstract derived types
Example
An extensible derived type may be abstract
type, abstract :: base_type
end type
Such a derived type may never be instantiated, such as by
type(base_type) t1
allocate(type(base_type) :: t2)
but a polymorphic object may have this as its declared type
class(base_type), allocatable :: t1
or
function f(t1)
class(base_type) t1
end function
Abstract types may have components and type-bound procedures
type, abstract :: base_type
integer i
contains
procedure func
procedure(func_iface), deferred :: def_func
end type
The procedure def_func is a deferred type-bound procedure with interface func_iface. Such a deferred type-bound procedure must be implemented by each extending type.
