diff --git a/doc/default_allocator.qbk b/doc/default_allocator.qbk
index f92e51b..74fa427 100644
--- a/doc/default_allocator.qbk
+++ b/doc/default_allocator.qbk
@@ -27,6 +27,19 @@ detects the absence of these members to provide more optimal construction.
 
 [endsect]
 
+[section Examples]
+
+The following snippet shows the use of this allocator as the default allocator
+for a container.
+
+```
+template<class Key, class Compare = std::less<Key>,
+    class Allocator = boost::default_allocator<Key> >
+class FlatSet;
+```
+
+[endsect]
+
 [section Reference]
 
 ```
@@ -64,7 +77,7 @@ constexpr bool operator==(const default_allocator<T>&,
     const default_allocator<U>&) noexcept;
 
 template<class T, class U>
-constexpr operator!=(const default_allocator<T>&,
+constexpr bool operator!=(const default_allocator<T>&,
     const default_allocator<U>&) noexcept;
 
 } /* boost */
@@ -73,7 +86,6 @@ constexpr operator!=(const default_allocator<T>&,
 [section Members]
 
 [variablelist
-
 [[`constexpr std::size_t max_size() const noexcept;`]
 [[variablelist
 [[Returns][The largest value `N` for which the call `allocate(N)` might
diff --git a/include/boost/core/default_allocator.hpp b/include/boost/core/default_allocator.hpp
index 20bf39e..a202f66 100644
--- a/include/boost/core/default_allocator.hpp
+++ b/include/boost/core/default_allocator.hpp
@@ -12,9 +12,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include <new>
 #include <climits>
 
-#if defined(BOOST_NO_CXX11_ALLOCATOR)
-#define BOOST_CORE_NO_CXX11_ALLOCATOR
-#elif defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION < 60000
+#if defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION < 60000
 #define BOOST_CORE_NO_CXX11_ALLOCATOR
 #endif
 
@@ -122,7 +120,7 @@ struct default_allocator {
     }
 #endif
 
-#if defined(BOOST_CORE_NO_CXX11_ALLOCATOR)
+#if defined(BOOST_NO_CXX11_ALLOCATOR) || defined(BOOST_CORE_NO_CXX11_ALLOCATOR)
     template<class U, class V>
     void construct(U* p, const V& v) {
         ::new(p) U(v);