diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..4ea774d
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,47 @@
+# Copyright (C) 2016 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)
+
+# Use Trusty to get a reasonably recent version of Boost.
+sudo: required
+dist: trusty
+
+language: c++
+
+addons:
+    apt:
+        packages:
+            - libboost-dev
+            - libboost-tools-dev
+
+matrix:
+    include:
+      - compiler: gcc
+        env: BJAM_TOOLSET=gcc
+      - compiler: gcc
+        env: BJAM_TOOLSET=gcc-std11
+      - compiler: clang
+        env: BJAM_TOOLSET=clang
+      - compiler: clang
+        env: BJAM_TOOLSET=clang-std11
+
+before_script:
+    - |
+        echo "using gcc : : g++-4.8 ;" > ~/user-config.jam
+        echo "using gcc : std11 : g++-4.8 --std=c++11 ;" >> ~/user-config.jam
+        echo "using clang : : clang++ ;" >> ~/user-config.jam
+        echo "using clang : std11 : clang++ --std=c++11 ;" >> ~/user-config.jam
+    - cat ~/user-config.jam
+    - touch Jamroot.jam
+
+script:
+    - cd ${TRAVIS_BUILD_DIR}/test
+    - bjam -q ${BJAM_TOOLSET} include=${TRAVIS_BUILD_DIR}/include
+    - cd ${TRAVIS_BUILD_DIR}/hash/test
+    - bjam -q ${BJAM_TOOLSET} include=${TRAVIS_BUILD_DIR}/include
+    - cd ${TRAVIS_BUILD_DIR}/forward/test
+    - bjam -q ${BJAM_TOOLSET} include=${TRAVIS_BUILD_DIR}/include
+    - cd ${TRAVIS_BUILD_DIR}/factory/test
+    - bjam -q ${BJAM_TOOLSET} include=${TRAVIS_BUILD_DIR}/include
+    - cd ${TRAVIS_BUILD_DIR}/overloaded_function/test
+    - bjam -q ${BJAM_TOOLSET} include=${TRAVIS_BUILD_DIR}/include
diff --git a/forward/test/forward_adapter.cpp b/forward/test/forward_adapter.cpp
index 2317ce7..09cef7e 100644
--- a/forward/test/forward_adapter.cpp
+++ b/forward/test/forward_adapter.cpp
@@ -44,6 +44,10 @@ public:
     {
         return -(l=r+val);
     }
+    char operator()(int& l, int& r)
+    {
+        return l=r+val;
+    }
 
     template <typename Sig>
     struct result
@@ -89,8 +93,11 @@ int main()
         // lvalue,lvalue
         BOOST_TEST(( is_same<
             result_of< f(int&, int&) >::type, char >::value ));
+        // result_of works differently for C++11 here, so compare
+        // with using it against test_func.
         BOOST_TEST(( is_same<
-            result_of< f const (int&, int&) >::type, char >::value ));
+            result_of< f const (int&, int&) >::type,
+            result_of< test_func<> const (int&, int&)>::type >::value ));
     }
 
     {
diff --git a/forward/test/lightweight_forward_adapter.cpp b/forward/test/lightweight_forward_adapter.cpp
index 7b0d304..dbd0f3f 100644
--- a/forward/test/lightweight_forward_adapter.cpp
+++ b/forward/test/lightweight_forward_adapter.cpp
@@ -44,6 +44,10 @@ public:
     {
         return -(l=r+val);
     }
+    char operator()(int & l, int & r)
+    {
+        return l=r+val;
+    }
 
     template <typename Sig>
     struct result
@@ -91,8 +95,11 @@ int main()
         // lvalue,lvalue
         BOOST_TEST(( is_same<
             result_of< f(ref, ref) >::type, char >::value ));
+        // result_of works differently for C++11 here, so compare
+        // with using it against test_func.
         BOOST_TEST(( is_same<
-            result_of< f const (ref, ref) >::type, char >::value ));
+            result_of< f const (ref, ref) >::type,
+            result_of< test_func<> const (int&, int&) >::type >::value ));
     }
     {
         using boost::noncopyable;
diff --git a/hash/examples/point.cpp b/hash/examples/point.cpp
index 6943342..f3d30e1 100644
--- a/hash/examples/point.cpp
+++ b/hash/examples/point.cpp
@@ -3,6 +3,11 @@
 // 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)
 
+// Force use of assert.
+#if defined(NDEBUG)
+#undef NDEBUG
+#endif
+
 #include <boost/functional/hash.hpp>
 #include <cassert>
 
diff --git a/hash/examples/portable.cpp b/hash/examples/portable.cpp
index 88f2fc7..511133e 100644
--- a/hash/examples/portable.cpp
+++ b/hash/examples/portable.cpp
@@ -3,6 +3,11 @@
 // 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)
 
+// Force use of assert.
+#if defined(NDEBUG)
+#undef NDEBUG
+#endif
+
 #include <boost/functional/hash.hpp>
 #include <cassert>
 
diff --git a/hash/test/hash_number_test.cpp b/hash/test/hash_number_test.cpp
index 242c731..9adb5c6 100644
--- a/hash/test/hash_number_test.cpp
+++ b/hash/test/hash_number_test.cpp
@@ -58,8 +58,6 @@ void numeric_extra_tests(typename
 template <class T>
 void numeric_test(T*)
 {
-    typedef boost::hash_detail::limits<T> limits;
-
     compile_time_tests((T*) 0);
 
     BOOST_HASH_TEST_NAMESPACE::hash<T> x1;
diff --git a/hash/test/hash_string_test.cpp b/hash/test/hash_string_test.cpp
index de8ca87..5f72d4e 100644
--- a/hash/test/hash_string_test.cpp
+++ b/hash/test/hash_string_test.cpp
@@ -38,6 +38,23 @@ void string_tests()
 #endif
 }
 
+void string0_tests()
+{
+    std::string x1(1, '\0');
+    std::string x2(2, '\0');
+    std::string x3(3, '\0');
+    std::string x4(10, '\0');
+
+    BOOST_HASH_TEST_NAMESPACE::hash<std::string> hasher;
+
+    BOOST_TEST(hasher(x1) != hasher(x2));
+    BOOST_TEST(hasher(x1) != hasher(x3));
+    BOOST_TEST(hasher(x1) != hasher(x4));
+    BOOST_TEST(hasher(x2) != hasher(x3));
+    BOOST_TEST(hasher(x2) != hasher(x4));
+    BOOST_TEST(hasher(x3) != hasher(x4));
+}
+
 #if !defined(BOOST_NO_STD_WSTRING)
 void wstring_tests()
 {
@@ -66,6 +83,7 @@ void wstring_tests()
 int main()
 {
     string_tests();
+    string0_tests();
 #if !defined(BOOST_NO_STD_WSTRING)
     wstring_tests();
 #endif
diff --git a/include/boost/functional/forward_adapter.hpp b/include/boost/functional/forward_adapter.hpp
index 796abd2..6023fc2 100644
--- a/include/boost/functional/forward_adapter.hpp
+++ b/include/boost/functional/forward_adapter.hpp
@@ -144,8 +144,30 @@ namespace boost
             : boost::result_of< BOOST_DEDUCED_TYPENAME c<Self>::t() >
         { };
 
-        template< class MD, class F, class FC >
-        struct forward_adapter_impl<MD,F,FC,0,0>
+        // WHen operator()() doesn't have any parameters, it can't
+        // be templatized and can't use SFINAE, so intead use class
+        // template parameter SFINAE to decide whether to instantiate it.
+
+        template <typename T, typename R = void>
+        struct forward_adapter_sfinae
+        {
+            typedef T type;
+        };
+
+        // This is the fallback for when there isn't an operator()(),
+        // need to create an operator() that will never instantiate
+        // so that using parent::operator() will work okay.
+        template< class MD, class F, class FC, class Enable = void>
+        struct forward_adapter_impl_zero
+        {
+            template <typename T> struct never_instantiate {};
+            template <typename T>
+            typename never_instantiate<T>::type operator()(T) const {}
+        };
+
+        template< class MD, class F, class FC>
+        struct forward_adapter_impl_zero<MD, F, FC,
+            typename forward_adapter_sfinae<typename boost::result_of< FC() >::type>::type>
         {
             inline typename boost::result_of< FC() >::type
             operator()() const
@@ -158,6 +180,13 @@ namespace boost
             {
                 return static_cast<MD*>(this)->target_function()();
             }
+        };
+
+        template< class MD, class F, class FC >
+        struct forward_adapter_impl<MD,F,FC,0,0>
+            : forward_adapter_impl_zero<MD,F,FC>
+        {
+            using forward_adapter_impl_zero<MD,F,FC>::operator();
 
         // closing brace gets generated by preprocessing code, below
 
diff --git a/include/boost/functional/hash/hash.hpp b/include/boost/functional/hash/hash.hpp
index 2fb9f21..0a8ceeb 100644
--- a/include/boost/functional/hash/hash.hpp
+++ b/include/boost/functional/hash/hash.hpp
@@ -212,7 +212,6 @@ namespace boost
             seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2);
         }
 
-        template <typename SizeT>
         inline void hash_combine_impl(boost::uint32_t& h1,
                 boost::uint32_t k1)
         {
@@ -229,12 +228,11 @@ namespace boost
         }
 
 
-// Don't define 64-bit hash combine on platforms with 64 bit integers,
+// Don't define 64-bit hash combine on platforms without 64 bit integers,
 // and also not for 32-bit gcc as it warns about the 64-bit constant.
 #if !defined(BOOST_NO_INT64_T) && \
         !(defined(__GNUC__) && ULONG_MAX == 0xffffffff)
 
-        template <typename SizeT>
         inline void hash_combine_impl(boost::uint64_t& h,
                 boost::uint64_t k)
         {
@@ -247,6 +245,10 @@ namespace boost
 
             h ^= k;
             h *= m;
+
+            // Completely arbitrary number, to prevent 0's
+            // from hashing to 0.
+            h += 0xe6546b64;
         }
 
 #endif // BOOST_NO_INT64_T
diff --git a/include/boost/functional/lightweight_forward_adapter.hpp b/include/boost/functional/lightweight_forward_adapter.hpp
index 637aa9e..2706d29 100644
--- a/include/boost/functional/lightweight_forward_adapter.hpp
+++ b/include/boost/functional/lightweight_forward_adapter.hpp
@@ -149,8 +149,31 @@ namespace boost
             : boost::result_of< BOOST_DEDUCED_TYPENAME c<Self>::t() >
         { };
 
-        template< class MD, class F, class FC >
-        struct lightweight_forward_adapter_impl<MD,F,FC,0,0>
+        // When operator() doesn't have any parameters, it can't
+        // be templatized and can't use SFINAE, so intead use class
+        // template parameter SFINAE to decide whether to instantiate it.
+
+        template <typename T, typename R = void>
+        struct lightweight_forward_adapter_sfinae
+        {
+            typedef T type;
+        };
+
+        // This is the fallback for when there isn't an operator()(),
+        // need to create an operator() that will never instantiate
+        // so that using parent::operator() will work okay.
+        template< class MD, class F, class FC, class Enable = void>
+        struct lightweight_forward_adapter_impl_zero
+            : lightweight_forward_adapter_result
+        {
+            template <typename T> struct never_instantiate {};
+            template <typename T>
+            typename never_instantiate<T>::type operator()(T) const {}
+        };
+
+        template< class MD, class F, class FC>
+        struct lightweight_forward_adapter_impl_zero<MD, F, FC,
+            typename lightweight_forward_adapter_sfinae<typename boost::result_of< FC() >::type>::type>
             : lightweight_forward_adapter_result
         {
             inline typename boost::result_of< FC() >::type
@@ -166,6 +189,12 @@ namespace boost
             }
         };
 
+        template< class MD, class F, class FC >
+        struct lightweight_forward_adapter_impl<MD,F,FC,0,0>
+            : lightweight_forward_adapter_impl_zero<MD,F,FC>
+        {
+        };
+
 #       define  BOOST_PP_FILENAME_1 \
             <boost/functional/lightweight_forward_adapter.hpp>
 #       define  BOOST_PP_ITERATION_LIMITS                                     \