----- Original Message ----- From: "John Maddock" <boost.regex@virgin.net> To: <boost@lists.boost.org> Sent: Saturday, June 26, 2010 6:22 PM Subject: Re: [boost] [math] common_factor template parameters
static_gcc and static_lcm have unsigned long parameters.
template < unsigned long Value1, unsigned long Value2 > struct boost::math::static_gcd;
Could these be changed to uintmax_t?
I would think so yes.
Do you need I make a ticket?
Is there any deep reason to don't define them for singed integers (intmax_t) also?
No, since the result for both functions is always taken as positive for one or more negative arguments. However.... unless we change the interface, it's hard to see how to accomplish this easily? Particularly as the unsigned version has a greater range?
Note that if the arguments might be negative then you could just write:
static_lcm<(arg1 < 0 ? -arg1 : arg1), (arg2 < 0 ? -arg2 : arg2)>::value
to achieve the same effect.
Ok, I will use it in this way. Joel Falcou suggested on another thread to define MPL integral constant metafunction for static_abs and static_sign. namespace XXX { template <typename ICT> abs : mpl::if_<is_unsigned<ICT::value_type>, ICT, mpl::integral_c<make_unsigned<ICT::value_type>, (ICT::value < 0 ? -ICT::value : ICT::value) > > {}; } Murillo, a GSOC student, is working on some metafunctions for integers including between others abs and sign. What do you think about a MPL integral constant metafunction having as parameters integral constant types on top of static_lcm? namespace XXX { template <typename ICT1, typename ICT2> lcm : mpl::integral_c<uintmax_t, static_lcm< XXX::abs<ICT1>::value, XXX::abs<ICT1>::value > > {}; } Should these metafunctions be added to the 'mpl' namespace? if not what could be the a good name for XXX? Best, Vicente