C++, can not copy 2 vectors to vector of pair

#include <vector>
#include <map>
#include <algorithm>


struct Item { double a, b; Item (double a_, double b_): a(a_), b(b_){}};
typedef std::pair <double, Item> TPair;
typedef std::vector <TPair> TData;


int main(int argc, char* argv[])
{
    std::vector <double> t1;
    std::vector <Item> t2;

    TData data;

    //Error
    std::transform (t1.begin(), t1.end(), data.begin(),
         std::bind2nd( std::ptr_fun( std::make_pair <double,Item > ), Item(0,0) ) );
}