sg14::span_ring: class template argument deduction #173
Description
to benefit from C++17's class template argument deduction the deduction rules on top of span_ring should be considered:
the example of deduction rules
template <typename ContiguousIterator>
ring_span(ContiguousIterator, ContiguousIterator)->ring_span<typename std::iterator_traits<ContiguousIterator>::value_type>;
template <typename ContiguousIterator, typename Popper>
ring_span(ContiguousIterator, ContiguousIterator, Popper)->ring_span<typename std::iterator_traits<ContiguousIterator>::value_type, Popper>;
template <typename ContiguousIterator>
ring_span(ContiguousIterator, ContiguousIterator, ContiguousIterator, std::size_t)->ring_span<typename std::iterator_traits<ContiguousIterator>::value_type>;
template <typename ContiguousIterator, typename Popper>
ring_span(ContiguousIterator, ContiguousIterator, ContiguousIterator, std::size_t, Popper)->ring_span<typename std::iterator_traits<ContiguousIterator>::value_type, Popper>;