"Cromwell Enage" <sponage@yahoo.com> wrote
The following expressions are currently illegal:
rational<int_<1>,int_<0> > rational_c<long,9,-5>
disallowing negative denominator seems a little harsh. 1 / -2 is a valid mathematical expression. [snip]
I've reimplemented rational<> so that it accepts any numeric constants M and N for which modulus<M,N> is a valid expression. That should improve its genericity.
FWIW some comments on rational... 1) rational should have a value_type for similarity with integral_c. ( eg plus <Numerator,Denominator>::type::value_type; ) 2) Because gcd is not a primitive operation( because it can be expressed solely in terms of others); Is there a need fo the 'impl and '::apply rigmarole. I think not(Same for abs, is_negative etc.)Why is this amount of implementation complexity necessary in gcd?. 3) However OTOH numerator<T> and denominator<T> need to be applicable to integral_c too(Otherwise there is no advantage over use of member ::denomnator) , but is a primitive operation; Therefore the 'impl rigmarole should be applied. denominator <int_<X> >:: type == int_<1>, numerator <int_<X> >:: type == int_<X> or whatever. It should be possible to mix rational and integral parameters pretty easily. FWIW Ive enclosed my rendition of denominator (hopefully boostified) in this method . Thanks for working on it though ... ;-) regards Andy Little