gistfile1.cpp

#include <iterator>
#include <type_traits>

template<class Iterator>
using move_if_noexcept_iterator = typename std::conditional<  
    !std::is_nothrow_move_constructible<
        typename std::iterator_traits<Iterator>::value_type
    >::value && std::is_copy_constructible<
        typename std::iterator_traits<Iterator>::value_type
    >::value,
    Iterator,
    std::move_iterator<Iterator>
>::type;

template<class Iterator>
constexpr move_if_noexcept_iterator<Iterator> make_move_if_noexcept_iterator(Iterator i) {
    return move_if_noexcept_iterator<Iterator>(i);
}