diff --git a/doc/hash_equality.qbk b/doc/hash_equality.qbk
index ca69f61f..7ca4396f 100644
--- a/doc/hash_equality.qbk
+++ b/doc/hash_equality.qbk
@@ -23,8 +23,8 @@ but not the equality predicate. For example, if you wanted to use the
 [import src_code/dictionary.cpp]
 [case_sensitive_dictionary_fnv]
 
-An example implementation of FNV-1, and some other hash functions are supplied
-in the examples directory.
+There is an [@../../libs/unordered/examples/fnv1.hpp implementation
+of FNV-1] in the examples directory.
 
 If you wish to use a different equality function,
 you will also need to use a matching hash function. For
diff --git a/doc/ref.xml b/doc/ref.xml
index da982b62..008e7c7c 100644
--- a/doc/ref.xml
+++ b/doc/ref.xml
@@ -181,7 +181,7 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
               <para>The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator.</para>
             </description>
           </constructor>
-          <constructor>
+          <constructor specifiers="explicit">
             <parameter name="a">
               <paramtype>Allocator const&amp;</paramtype>
             </parameter>
@@ -928,7 +928,7 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
               <para>The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator.</para>
             </description>
           </constructor>
-          <constructor>
+          <constructor specifiers="explicit">
             <parameter name="a">
               <paramtype>Allocator const&amp;</paramtype>
             </parameter>
@@ -1685,7 +1685,7 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
               <para>The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator.</para>
             </description>
           </constructor>
-          <constructor>
+          <constructor specifiers="explicit">
             <parameter name="a">
               <paramtype>Allocator const&amp;</paramtype>
             </parameter>
@@ -2483,7 +2483,7 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
               <para>The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator.</para>
             </description>
           </constructor>
-          <constructor>
+          <constructor specifiers="explicit">
             <parameter name="a">
               <paramtype>Allocator const&amp;</paramtype>
             </parameter>
@@ -3062,4 +3062,4 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
         </class>
       </namespace>
     </header>
-  </library-reference>
\ No newline at end of file
+  </library-reference>
diff --git a/doc/src_code/dictionary.cpp b/doc/src_code/dictionary.cpp
index 721952a0..1f8ead92 100644
--- a/doc/src_code/dictionary.cpp
+++ b/doc/src_code/dictionary.cpp
@@ -6,7 +6,7 @@
 #include <boost/unordered_map.hpp>
 #include <boost/detail/lightweight_test.hpp>
 #include <boost/algorithm/string/predicate.hpp>
-#include "../../examples/hash_functions/fnv-1.hpp"
+#include "../../examples/fnv1.hpp"
 
 //[case_insensitive_functions
     struct iequal_to
diff --git a/examples/fnv1.hpp b/examples/fnv1.hpp
new file mode 100644
index 00000000..60bf8985
--- /dev/null
+++ b/examples/fnv1.hpp
@@ -0,0 +1,66 @@
+
+// Copyright 2008 Daniel James.
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// This code is also released into the public domain.
+
+// Algorithm from: http://www.isthe.com/chongo/tech/comp/fnv/
+
+#include <string>
+
+namespace hash
+{
+    template <std::size_t FnvPrime, std::size_t OffsetBasis>
+    struct basic_fnv_1
+    {
+        std::size_t operator()(std::string const& text) const
+        {
+            std::size_t hash = OffsetBasis;
+            for(std::string::const_iterator it = text.begin(), end = text.end();
+                    it != end; ++it)
+            {
+                hash *= FnvPrime;
+                hash ^= *it;
+            }
+
+            return hash;
+        }
+    };
+
+    template <std::size_t FnvPrime, std::size_t OffsetBasis>
+    struct basic_fnv_1a
+    {
+        std::size_t operator()(std::string const& text) const
+        {
+            std::size_t hash = OffsetBasis;
+            for(std::string::const_iterator it = text.begin(), end = text.end();
+                    it != end; ++it)
+            {
+                hash ^= *it;
+                hash *= FnvPrime;
+            }
+
+            return hash;
+        }
+    };
+
+    // For 32 bit machines:
+    const std::size_t fnv_prime = 16777619u;
+    const std::size_t fnv_offset_basis = 2166136261u;
+
+    // For 64 bit machines:
+    // const std::size_t fnv_prime = 1099511628211u;
+    // const std::size_t fnv_offset_basis = 14695981039346656037u;
+
+    // For 128 bit machines:
+    // const std::size_t fnv_prime = 309485009821345068724781401u;
+    // const std::size_t fnv_offset_basis = 275519064689413815358837431229664493455u;
+
+    // For 256 bit machines:
+    // const std::size_t fnv_prime = 374144419156711147060143317175368453031918731002211u;
+    // const std::size_t fnv_offset_basis = 100029257958052580907070968620625704837092796014241193945225284501741471925557u;
+
+    typedef basic_fnv_1<fnv_prime, fnv_offset_basis> fnv_1;
+    typedef basic_fnv_1a<fnv_prime, fnv_offset_basis> fnv_1a;
+}
diff --git a/examples/hash_functions/fnv-1.hpp b/examples/hash_functions/fnv-1.hpp
deleted file mode 100644
index 9caf1687..00000000
--- a/examples/hash_functions/fnv-1.hpp
+++ /dev/null
@@ -1,71 +0,0 @@
-
-// Copyright 2008 Daniel James.
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-// Algorithm from: http://www.isthe.com/chongo/tech/comp/fnv/
-
-#include <string>
-
-namespace hash
-{
-    template <std::size_t FnvPrime, std::size_t OffsetBias>
-    struct basic_fnv_1
-    {
-        std::size_t operator()(std::string const& text) const
-        {
-            std::size_t hash = OffsetBias;
-            for(std::string::const_iterator it = text.begin(), end = text.end();
-                    it != end; ++it)
-            {
-                hash *= FnvPrime;
-                hash ^= *it;
-            }
-
-            return hash;
-        }
-    };
-
-    template <std::size_t FnvPrime, std::size_t OffsetBias>
-    struct basic_fnv_1a
-    {
-        std::size_t operator()(std::string const& text) const
-        {
-            std::size_t hash = OffsetBias;
-            for(std::string::const_iterator it = text.begin(), end = text.end();
-                    it != end; ++it)
-            {
-                hash ^= *it;
-                hash *= FnvPrime;
-            }
-
-            return hash;
-        }
-    };
-
-    // TODO: Select Bias & Prime base on the size of std::size_t.
-    //
-    // 32 bit FNV_prime = 16777619
-    // 64 bit FNV_prime = 1099511628211
-    // 128 bit FNV_prime = 309485009821345068724781401
-    // 256 bit FNV_prime = 374144419156711147060143317175368453031918731002211
-    //
-    // 32 bit offset_basis = 2166136261
-    // 64 bit offset_basis = 14695981039346656037
-    // 128 bit offset_basis = 275519064689413815358837431229664493455
-    // 256 bit offset_basis = 100029257958052580907070968620625704837092796014241193945225284501741471925557
-
-    const std::size_t fnv_prime = 16777619;
-    // 64 bit FNV_prime = 1099511628211
-    // 128 bit FNV_prime = 309485009821345068724781401
-    // 256 bit FNV_prime = 374144419156711147060143317175368453031918731002211
-
-    const std::size_t fnv_offset_bias = 2166136261u;
-    // 64 bit offset_basis = 14695981039346656037
-    // 128 bit offset_basis = 275519064689413815358837431229664493455
-    // 256 bit offset_basis = 100029257958052580907070968620625704837092796014241193945225284501741471925557
-
-    typedef basic_fnv_1<fnv_prime, fnv_offset_bias> fnv_1;
-    typedef basic_fnv_1a<fnv_prime, fnv_offset_bias> fnv_1a;
-
-}
diff --git a/include/boost/unordered_map.hpp b/include/boost/unordered_map.hpp
index 093c7697..5f711650 100644
--- a/include/boost/unordered_map.hpp
+++ b/include/boost/unordered_map.hpp
@@ -107,8 +107,7 @@ namespace boost
         {
         }
 
-        // TODO: Should this be explicit?
-        unordered_map(allocator_type const& a)
+        explicit unordered_map(allocator_type const& a)
             : base(boost::unordered_detail::default_initial_bucket_count,
                 hasher(), key_equal(), a)
         {
@@ -504,7 +503,7 @@ namespace boost
         {
         }
 
-        unordered_multimap(allocator_type const& a)
+        explicit unordered_multimap(allocator_type const& a)
             : base(boost::unordered_detail::default_initial_bucket_count,
                 hasher(), key_equal(), a)
         {
diff --git a/include/boost/unordered_set.hpp b/include/boost/unordered_set.hpp
index 1addae10..0f34c0fd 100644
--- a/include/boost/unordered_set.hpp
+++ b/include/boost/unordered_set.hpp
@@ -104,8 +104,7 @@ namespace boost
         {
         }
 
-        // TODO: Should this be explicit?
-        unordered_set(allocator_type const& a)
+        explicit unordered_set(allocator_type const& a)
             : base(boost::unordered_detail::default_initial_bucket_count,
                 hasher(), key_equal(), a)
         {
@@ -473,8 +472,7 @@ namespace boost
         {
         }
 
-        // TODO: Should this be explicit?
-        unordered_multiset(allocator_type const& a)
+        explicit unordered_multiset(allocator_type const& a)
             : base(boost::unordered_detail::default_initial_bucket_count,
                 hasher(), key_equal(), a)
         {