 <a name="portability">Portability</a></h3>

    <p>Many compilers (<i>e.g.</i> MSVC 6.3, GCC 2.95.2) will not enforce the
    requirements in the operator template tables unless the operations which
    depend on them are actually used. This is not standard-conforming
    behavior. In particular, although it would be convenient to derive all
    your classes which need binary operators from the <code><a href=
    "#operators1">operators&lt;&gt;</a></code> and <code><a href=
    "#operators2">operators2&lt;