[any.modifiers] fix emplace return type for 'any' (#1545)

LWG issue 2857 was applied verbatim, without noticing
that 'ValueType' had been previously changed to 'T'.
This makes things consistent by choosing 'T' as the
simpler form, more consistent with 'optional' and
'variant'.

Author: Alisdair Meredith

source/utilities.tex

@@ -5547,9 +5547,9 @@
 
   // \ref{any.modifiers}, modifiers
   template <class T, class... Args>
-    decay_t<ValueType>& emplace(Args&& ...);
+    decay_t<T>& emplace(Args&& ...);
   template <class T, class U, class... Args>
-    decay_t<ValueType>& emplace(initializer_list<U>, Args&&...);
+    decay_t<T>& emplace(initializer_list<U>, Args&&...);
   void reset() noexcept;
   void swap(any& rhs) noexcept;
 
@@ -5807,7 +5807,7 @@
 \indexlibrarymember{emplace}{any}%
 \begin{itemdecl}
 template <class T, class... Args>
-  decay_t<ValueType>& emplace(Args&&... args);
+  decay_t<T>& emplace(Args&&... args);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -5845,7 +5845,7 @@
 \indexlibrarymember{emplace}{any}%
 \begin{itemdecl}
 template <class T, class U, class... Args>
-  decay_t<ValueType>& emplace(initializer_list<U> il, Args&&... args);
+  decay_t<T>& emplace(initializer_list<U> il, Args&&... args);
 \end{itemdecl}
 
 \begin{itemdescr}