LWG3918 std::uninitialized_move/_n and guaranteed copy elision

[specialized.algorithms.general] Changed to "function templates" as per #6265.

Author: burblebee

source/algorithms.tex

@@ -11167,13 +11167,20 @@
 
 \pnum
 Some algorithms specified in \ref{specialized.algorithms}
-make use of the exposition-only function template
-\tcode{\placeholdernc{voidify}}:
+make use of the following exposition-only function templates:
 \begin{codeblock}
 template<class T>
   constexpr void* @\placeholdernc{voidify}@(T& obj) noexcept {
     return addressof(obj);
   }
+
+template<class I>
+  decltype(auto) @\exposid{deref-move}@(I& it) {
+    if constexpr (is_lvalue_reference_v<decltype(*it)>)
+      return std::move(*it);
+    else
+      return *it;
+  }
 \end{codeblock}
 
 \rSec2[special.mem.concepts]{Special memory concepts}
@@ -11550,7 +11557,7 @@
 \begin{codeblock}
 for (; first != last; (void)++result, ++first)
   ::new (@\placeholdernc{voidify}@(*result))
-    typename iterator_traits<NoThrowForwardIterator>::value_type(std::move(*first));
+    typename iterator_traits<NoThrowForwardIterator>::value_type(@\exposid{deref-move}@(first));
 return result;
 \end{codeblock}
 \end{itemdescr}
@@ -11610,7 +11617,7 @@
 \begin{codeblock}
 for (; n > 0; ++result, (void) ++first, --n)
   ::new (@\placeholdernc{voidify}@(*result))
-    typename iterator_traits<NoThrowForwardIterator>::value_type(std::move(*first));
+    typename iterator_traits<NoThrowForwardIterator>::value_type(@\exposid{deref-move}@(first));
 return {first, result};
 \end{codeblock}
 \end{itemdescr}