Ticket #4228: test_vector.cpp

#include "boost/fusion/adapted/mpl.hpp"
#include "boost/fusion/container/vector/convert.hpp"
#include "boost/fusion/sequence/intrinsic/at.hpp"
#include "boost/fusion/view/transform_view.hpp"

using namespace boost;

struct TestType0 : mpl::int_<0> {};
struct TestType1 : mpl::int_<1> {};
struct TestType2 : mpl::int_<2> {};
struct TestType3 : mpl::int_<3> {};
struct TestType4 : mpl::int_<4> {};
struct TestType5 : mpl::int_<5> {};
struct TestType6 : mpl::int_<6> {};
struct TestType7 : mpl::int_<7> {};
struct TestType8 : mpl::int_<8> {};
struct TestType9 : mpl::int_<9> {};


typedef fusion::vector10
<
    TestType0,
    TestType1,
    TestType2,
    TestType3,
    TestType4,
    TestType5,
    TestType6,
    TestType7,
    TestType8
> MainTypes;


struct OddWidget  { int dummy_; };
struct EvenWidget { int dummy_; };

struct Transformer
{
    template <typename Sig>
    struct result;

    template <typename T>
    struct result<Transformer( T )> : mpl::if_c<T::value % 2, OddWidget, EvenWidget> {};
};


int main()
{
    typedef boost::fusion::transform_view
            <
                MainTypes,
                Transformer
            > WidgetsView;

    typedef typename boost::fusion::result_of::as_vector
            <
                WidgetsView
            >::type WidgetContainer;

    typedef fusion::result_of::find <MainTypes, TestType4>::type MainTypesIterator;
    typedef fusion::result_of::begin<MainTypes           >::type MainTypesBegining;

    typedef fusion::result_of::distance<MainTypesBegining, MainTypesIterator>::type Index;

    WidgetContainer widgets;
    return fusion::at<Index>( widgets ).dummy_;
}