Improved range detection supporting ADL

zmq.hpp

@@ -156,6 +156,22 @@ namespace zmq
 #ifdef ZMQ_CPP11
 namespace detail
 {
+namespace ranges
+{
+using std::begin;
+using std::end;
+template<class T>
+auto begin(T&& r) -> decltype(begin(std::forward<T>(r)))
+{
+    return begin(std::forward<T>(r));
+}
+template<class T>
+auto end(T&& r) -> decltype(end(std::forward<T>(r)))
+{
+    return end(std::forward<T>(r));
+}
+} // namespace ranges
+
 template<class T> using void_t = void;
 
 template<class Iter>
@@ -163,7 +179,7 @@ using iter_value_t = typename std::iterator_traits<Iter>::value_type;
 
 template<class Range>
 using range_iter_t = decltype(
-  std::begin(std::declval<typename std::remove_reference<Range>::type &>()));
+  ranges::begin(std::declval<typename std::remove_reference<Range>::type &>()));
 
 template<class Range>
 using range_value_t = iter_value_t<range_iter_t<Range>>;
@@ -176,8 +192,8 @@ template<class T>
 struct is_range<
   T,
   void_t<decltype(
-    std::begin(std::declval<typename std::remove_reference<T>::type &>())
-    == std::end(std::declval<typename std::remove_reference<T>::type &>()))>>
+    ranges::begin(std::declval<typename std::remove_reference<T>::type &>())
+    == ranges::end(std::declval<typename std::remove_reference<T>::type &>()))>>
     : std::true_type
 {
 };
@@ -316,7 +332,8 @@ class message_t
                detail::is_range<Range>::value
                && std::is_trivially_copyable<detail::range_value_t<Range>>::value
                && !std::is_same<Range, message_t>::value>::type>
-    explicit message_t(const Range &rng) : message_t(std::begin(rng), std::end(rng))
+    explicit message_t(const Range &rng) :
+        message_t(detail::ranges::begin(rng), detail::ranges::end(rng))
     {
     }
 #endif