frozen?

/*
 *  call-seq:
 *     array.frozen?  -> true or false
 *
 *  Return <code>true</code> if this array is frozen (or temporarily frozen
 *  while being sorted).
 */

static VALUE
rb_ary_frozen_p(ary)
    VALUE ary;
{
    if (OBJ_FROZEN(ary)) return Qtrue;
    if (FL_TEST(ary, ARY_TMPLOCK)) return Qtrue;
    return Qfalse;
}