diff --git a/types/traits.hpp b/types/traits.hpp
index f5a9a6c3..1826889d 100644
--- a/types/traits.hpp
+++ b/types/traits.hpp
@@ -294,9 +294,18 @@ using nth_argument_t = typename nth_argument<N, FuncT>::type;
 
 
 ///////////////////////////////////////////////////////////////////////////////
+/// A trait that tests if a type `T` is a container type.
+///
+/// That is, a type that has:
+///  *  container typedefs such as value_type, reference, iterator, etc.
+///  *  viable std::begin/std::end overloads
+///
+/// Defaults to false.
 template <typename T, typename = std::void_t<>>
 struct is_container : public std::false_type {};
 
+
+///----------------------------------------------------------------------------
 template <typename T>
 struct is_container<
     T,
@@ -307,15 +316,14 @@ struct is_container<
         typename T::iterator,
         typename T::const_iterator,
         typename T::difference_type,
-        typename T::size_type
+        typename T::size_type,
+        decltype(std::end   (std::declval<T> ())),
+        decltype(std::begin (std::declval<T> ()))
     >
 > : public std::true_type {};
 
 
-template <size_t N, typename ValueT>
-struct is_container<std::array<ValueT,N>> : public std::true_type {};
-
-
+//-----------------------------------------------------------------------------
 template <typename T>
 constexpr auto is_container_v = is_container<T>::value;