default_proc=

static VALUE
rb_hash_set_default_proc(VALUE hash, VALUE proc)
{
    VALUE b;

    rb_hash_modify(hash);
    b = rb_check_convert_type(proc, T_DATA, "Proc", "to_proc");
    if (NIL_P(b) || !rb_obj_is_proc(b)) {
        rb_raise(rb_eTypeError,
                 "wrong default_proc type %s (expected Proc)",
                 rb_obj_classname(proc));
    }
    proc = b;
    default_proc_arity_check(proc);
    RHASH_IFNONE(hash) = proc;
    FL_SET(hash, HASH_PROC_DEFAULT);
    return proc;
}