"Peder Holt" <peder.holt@gmail.com> wrote
I did some tests on VC8 beta, and it compiles the testcase in half the time compared to the present implementation of typeof_impl. As far as I have been able to test, it also works around the compiler bug for VC8 discussed earlier.
Here is a more detailed sketch of the proposed solution:
namespace boost {namespace type_of{ template<typename T> struct encode_result { typedef typename encode_type<BOOST_TYPEOF_VECTOR(0)<>, T>::type encoded_type; typedef typename mpl::size<encoded_type>::type size; char (&value0)[...]; char (&value1)[...]; char (&value2)[...]; ... char (&value50)[...]; };
template<class T> encode_result<T> typeof_result(const T&); }} #define BOOST_TYPEOF_AT(n, expr) sizeof(boost::type_of::typeof_result(expr).BOOST_PP_CAT(value,n))
Interesting... Let me guess: char(&value2)[mpl::at<encode<T>::type, mpl::int<(2 < size) ? 2 : 0>
::type::value]; //?
Regards, Arkadiy