Library /sys$common/syshlp/dbg$help.hlb DEBUG, Language Support, CC, Structures and Unions  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    You can examine structures in their entirety or on a member-by-
    member basis, and deposit data into structures one member at a
    time.

    To reference members of a structure or union, use the usual C
    syntax for such references. That is, if variable p is a pointer
    to a structure, you can reference member y of that structure with
    the expression p ->y. If variable x refers to the base of the
    storage allocated for a structure, you can refer to a member of
    that structure with the x.y expression.

    The debugger uses C type-checking rules to reference members of
    a structure or union. For example, in the case of x.y, y need
    not be a member of x; it is treated as an offset with a type.
    When such a reference is ambiguous-when there is more than one
    structure with a member y-the debugger attempts to resolve the
    reference according to the following rules. The same rules for
    resolving the ambiguity of a reference to a member of a structure
    or union apply to both x.y and p ->y.

    o  If only one of the members, y, belongs in the structure or
       union, x, that is the one that is referenced.

    o  If only one of the members, y, is in the same scope as x, then
       that is the one that is referenced.

    You can always give a path name with the reference to x to narrow
    the scope that is used and to resolve the ambiguity. The same
    path name is used to look up both x and y.