On Tue, May 20, 2008 at 4:13 PM, klaus triendl <klaus@triendl.eu> wrote:
Hmm, I didn't look thoroughly at it but wouldn't it be possible to remove these overloads? I've seen a proposal for bool_set that doesn't overload (anymore) the two logical operators.
I don't think you can get rid of the overloads. The overloads are needed to implement the truth tables (see http://www.boost.org/doc/libs/1_35_0/doc/html/boost/logic/operator_id257657.... http://www.boost.org/doc/libs/1_35_0/doc/html/boost/logic/operator!_id340819... ). In order to remove them, you need a conversion C: tribool-> bool that preserves all the truth tables, and is an homomorphism, i.e. C( op(X) ) == op( C(X) ) and C( X op Y ) == C(X) op C(Y) Unfortunately, if such conversion existed, then : C(indeterminate) = C(!indeterminate) = !C(indeterminate) that is impossible for a bool. Do you really need tribool semantics, or you just needed something like optional<bool>? One thing that can be done is to use expression templates to build the operator expressions, and implement short circuit evaluation on top of them, but then you have to pay attention to how you build your expression, because you have to explicitly delay expressions like *a_bool_pointer. Corrado --
Klaus
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-- __________________________________________________________________________ dott. Corrado Zoccolo mailto:czoccolo@gmail.com PhD - Department of Computer Science - University of Pisa, Italy -------------------------------------------------------------------------- The self-confidence of a warrior is not the self-confidence of the average man. The average man seeks certainty in the eyes of the onlooker and calls that self-confidence. The warrior seeks impeccability in his own eyes and calls that humbleness. Tales of Power - C. Castaneda