std::chrono and cout

I am trying to switch to the c++11 headers and one of those is chrono. But my problem is that I cant cout the result of time operations. For example:

auto t=std::chrono::high_resolution_clock::now();
cout<<t.time_since_epoch();

gives:

initializing argument 1 of ‘std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&) [with _CharT = char, _Traits = std::char_traits<char>, _Tp = std::chrono::duration<long int, std::ratio<1l, 1000000l> >]’ ... /usr/include/c++/4.6/ostream

cout<<(uint64_t)t.time_since_epoch();

gives invalid cast