That's fantastic! Thank you for your recommendation. Στις 4:32 μ.μ. Παρασκευή, 20 Μαρτίου 2015, ο/η Mathias Gaunard <mathias.gaunard@ens-lyon.org> έγραψε: On 20/03/2015 17:13, costis glynos wrote:
On 20/03/2015 16:59, costis glynos wrote:
Hello,Is there any interest in a library which automatically sorts types from smallest to largest at compile time?The benefit would be the automatic Data Structure Alignment and potential improvement in performance.Foo<int,bool,Custom16ByteType,char,double,short> foo_1; //normal Foo<int,bool,Custom16ByteType,char,double,short> foo_2; //using the TypeSort output: size of foo_1 = 48 size of foo_2 = 32 Kind Regards,
There is already a sort meta-function in Boost.MPL. <http://www.boost.org/doc/libs/1_57_0/libs/mpl/doc/refmanual/sort.html>
Sweet! Thanks for bringing this to my attention.
You also need to use Boost.Fusion to make it into a tuple at the end, since this is what you want. Here is an example: #include <boost/mpl/sort.hpp> #include <boost/mpl/vector.hpp> #include <boost/mpl/sizeof.hpp> #include <boost/fusion/include/as_vector.hpp> #include <boost/fusion/adapted/mpl.hpp> #include <iostream> int main() { namespace mpl = boost::mpl; namespace fusion = boost::fusion; typedef mpl::vector<short, int, short> types; typedef mpl::sort<types, mpl::less< mpl::sizeof_<mpl::_1> , mpl::sizeof_<mpl::_2> > >::type sorted_types; typedef fusion::result_of::as_vector<sorted_types>::type tuple; tuple t; std::cout << sizeof(t) << std::endl; // 8 instead of 12 } This appears to work. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost