Derived data type pointer? -

i'm trying convert c code fortran 90. there way in fortran define derived data type pointer? code below example of i'm talking about.

typedef struct _rkmatrix rkmatrix; typedef rkmatrix *prkmatrix; 

the struct _rkmatrix defined outside snippet of code.

example declarations linked list:

type mycustom_type    real :: value    type (mycustom_type), pointer :: next => null () end type mycustom_type  type (mycustom_type), pointer :: head_of_list