Qualifiers
==========

Transitive qualifiers
---------------------

It can be useful to specify that a return value should be
const if and only if the parameter (or perhaps the "this"-object)
is const.

Syntax test:

    func find
        aliased maybevar TreeNode tree
        string name
    return
        aliased maybevar TreeNode res
    end

Or (best?):

    func find
        returned TreeNode tree
        string name
    return
        fromparam TreeNode res
    end

Or, using "parametric qualifiers":

    func find
    qualparam q
        q TreeNode tree
        string name
    return
        q TreeNode res
    end