[Boost-users] mpl documentation question

Documentation for mpl::less<T> has the following section: Expression semantics For any Integral Constants c1 and c2: typedef less::type r; Return type:Integral Constant. Semantics:Equivalent to typedef bool_< (c1::value < c2::value) > r; typedef less r; // a Return type:Integral Constant. Semantics:Equivalent to struct r : less::type {}; //b if //a is used then the following yields bool_<true> is_same< less, r> if // b is used then the following yields bool_<false> is_same< less, r> So in what sense are //a and // b equivalent? Robert Ramey