DEPRECATED
SYNOPSIS
        mapping map_mapping(mapping m, string func, string|object ob, ...)
        mapping map_mapping(mapping m, closure cl, ...)

DESCRIPTION
        ob->func() is called resp. cl applied to every element in the mapping,
        with the key of the element as first argument, and then the extra args
        that were given to map_mapping (these args must not be protected
        references like &(i[0])).  The data item in the mapping is replaced by
        the return value of the function. ob can also be a file_name of an
        object.

        If <ob> is omitted, or neither a string nor an object, it
        defaults to this_object().

        Note that if mapping m has more than one value per key, these
        are ignored: the resulting mapping always has one value per key.

        Also note that the behaviour of this function is different from
        map_array().

EXAMPLE
        m = mkmapping(users());
        m = map_mapping(m, #'environment);

HISTORY
        In LDMud 3.2.6 renamed to map_indices().
        Since LDMud 3.2.9, not available if driver is compiled without
          USE_DEPRECATED.

SEE ALSO
        map(E), filter(E), filter_indices(E), walk_mapping(E), member(E),
        m_contains(E)