LWG3428 single_view's in place constructor should be explicit

Author: burblebee

source/ranges.tex

@@ -1931,7 +1931,7 @@
     constexpr explicit single_view(T&& t);
     template<class... Args>
       requires @\libconcept{constructible_from}@<T, Args...>
-    constexpr single_view(in_place_t, Args&&... args);
+    constexpr explicit single_view(in_place_t, Args&&... args);
 
     constexpr T* begin() noexcept;
     constexpr const T* begin() const noexcept;
@@ -1970,7 +1970,7 @@
 \begin{itemdecl}
 template<class... Args>
   requires @\libconcept{constructible_from}@<T, Args...>
-constexpr single_view(in_place_t, Args&&... args);
+constexpr explicit single_view(in_place_t, Args&&... args);
 \end{itemdecl}
 
 \begin{itemdescr}