step 2

include/seqan3/alphabet/composite/alphabet_tuple_base.hpp

@@ -348,16 +348,16 @@ class alphabet_tuple_base :
      * \stableapi{Since version 3.1.}
      */
     template <size_t index>
-    friend constexpr auto get(alphabet_tuple_base & l) noexcept
+    constexpr auto get() noexcept
     {
         static_assert(index < sizeof...(component_types), "Index out of range.");
 
         using t = meta::at_c<component_list, index>;
         t val{};
 
-        seqan3::assign_rank_to(l.to_component_rank<index>(), val);
+        seqan3::assign_rank_to(to_component_rank<index>(), val);
 
-        return component_proxy<t, index>{val, l};
+        return component_proxy<t, index>{val, *this};
     }
 
     /*!\copybrief get
@@ -382,13 +382,13 @@ class alphabet_tuple_base :
      * \stableapi{Since version 3.1.}
      */
     template <size_t index>
-    friend constexpr auto get(alphabet_tuple_base const & l) noexcept
+    constexpr auto get() const noexcept
     {
         static_assert(index < sizeof...(component_types), "Index out of range.");
 
         using t = meta::at_c<component_list, index>;
 
-        return seqan3::assign_rank_to(l.to_component_rank<index>(), t{});
+        return seqan3::assign_rank_to(to_component_rank<index>(), t{});
     }
 
     /*!\copybrief get
@@ -762,11 +762,29 @@ class alphabet_tuple_base<derived_type, component_types...>::component_proxy : p
     //!\}
 };
 
+//!\brief The same as [std::get](https://en.cppreference.com/w/cpp/utility/tuple/get) on an std::tuple.
+//!\relates seqan3::alphabet_tuple_base
+template <size_t index, typename ...types>
+constexpr auto get(alphabet_tuple_base<types...> & l) noexcept
+{
+    return l.template get<index>();
+}
+
+//!\brief The same as [std::get](https://en.cppreference.com/w/cpp/utility/tuple/get) on an std::tuple.
+//!\relates seqan3::alphabet_tuple_base
+template <size_t index, typename ...types>
+constexpr auto get(alphabet_tuple_base<types...> const & l) noexcept
+{
+    return l.template get<index>();
+}
+
 } // namespace seqan3
 
 namespace std
 {
 
+using seqan3::get;
+
 /*!\brief Obtains the type of the specified element.
  * \implements seqan3::transformation_trait
  * \ingroup composite

include/seqan3/alphabet/quality/qualified.hpp

@@ -243,3 +243,10 @@ qualified(sequence_alphabet_type &&, quality_alphabet_type &&)
     -> qualified<std::decay_t<sequence_alphabet_type>, std::decay_t<quality_alphabet_type>>;
 
 } // namespace seqan3
+
+namespace std
+{
+
+using seqan3::get;
+
+} // namespace std

include/seqan3/std/ranges

@@ -250,6 +250,27 @@ using ::ranges::cpp20::views::keys;
 using ::ranges::cpp20::views::values;
 } // namespace views
 
+// [range.elements]
+namespace views
+{
+
+namespace
+{
+
+template <size_t index>
+inline constexpr auto elements = std::ranges::views::transform([] (auto && in) -> decltype(auto)
+{
+    using get_return_t = decltype(std::get<index>(std::forward<decltype(in)>(in)));
+    using return_t = std::conditional_t<std::is_rvalue_reference_v<get_return_t>,
+                                        std::remove_reference_t<get_return_t>,
+                                        get_return_t>;
+    return static_cast<return_t>(std::get<index>(std::forward<decltype(in)>(in)));
+});
+
+} // anonymous namespace
+
+} // namespace views
+
 } // anonymous namespace
 
 } // namespace std::ranges

include/seqan3/utility/tuple/pod_tuple.hpp

@@ -288,63 +288,7 @@ constexpr auto const && get(seqan3::pod_tuple<arg_types...> const && t) noexcept
 namespace std
 {
 
-//!\cond
-template <std::size_t i, typename ...types>
-constexpr auto & get(seqan3::pod_tuple<types...> & t) noexcept
-    requires (i < sizeof...(types))
-{
-    return seqan3::get<i>(t);
-}
-
-template <std::size_t i, typename ...types>
-constexpr auto const & get(seqan3::pod_tuple<types...> const & t) noexcept
-    requires (i < sizeof...(types))
-{
-    return seqan3::get<i>(t);
-}
-
-template <std::size_t i, typename ...types>
-constexpr auto && get(seqan3::pod_tuple<types...> && t) noexcept
-    requires (i < sizeof...(types))
-{
-    return seqan3::get<i>(std::move(t));
-}
-
-template <std::size_t i, typename ...types>
-constexpr auto const && get(seqan3::pod_tuple<types...> const && t) noexcept
-    requires (i < sizeof...(types))
-{
-    return seqan3::get<i>(std::move(t));
-}
-
-template <typename type, typename ...types>
-constexpr auto & get(seqan3::pod_tuple<types...> & t) noexcept
-    requires (seqan3::pack_traits::count<type, types...> == 1)
-{
-    return seqan3::get<type>(t);
-}
-
-template <typename type, typename ...types>
-constexpr auto const & get(seqan3::pod_tuple<types...> const & t) noexcept
-    requires (seqan3::pack_traits::count<type, types...> == 1)
-{
-    return seqan3::get<type>(t);
-}
-
-template <typename type, typename ...types>
-constexpr auto && get(seqan3::pod_tuple<types...> && t) noexcept
-    requires (seqan3::pack_traits::count<type, types...> == 1)
-{
-    return seqan3::get<type>(std::move(t));
-}
-
-template <typename type, typename ...types>
-constexpr auto const && get(seqan3::pod_tuple<types...> const && t) noexcept
-    requires (seqan3::pack_traits::count<type, types...> == 1)
-{
-    return seqan3::get<type>(std::move(t));
-}
-//!\endcond
+using seqan3::get;
 
 /*!\brief Obtains the type of the specified element.
  * \implements seqan3::transformation_trait