diff --git a/doc/pointer_traits.qbk b/doc/pointer_traits.qbk
index d0247fa..716d815 100644
--- a/doc/pointer_traits.qbk
+++ b/doc/pointer_traits.qbk
@@ -1,5 +1,5 @@
 [/
-Copyright 2017-2018 Glen Joseph Fernandes
+Copyright 2017-2021 Glen Joseph Fernandes
 (glenjofe@gmail.com)
 
 Distributed under the Boost Software License, Version 1.0.
@@ -47,68 +47,87 @@ void function(Allocator& a)
 
 ```
 namespace boost {
-  template<class T> struct pointer_traits {
+
+template<class T>
+struct pointer_traits {
     typedef T pointer;
     typedef ``['see below]`` element_type;
     typedef ``['see below]`` difference_type;
 
-    template<class U> struct rebind_to { typedef ``['see below]`` type; };
-    template<class U> using rebind = typename rebind_to<U>::type;
+    template<class U>
+    struct rebind_to {
+        typedef ``['see below]`` type;
+    };
 
-    static pointer pointer_to(``['see below]`` v);
-  };
+    template<class U>
+    using rebind = typename rebind_to<U>::type;
 
-  template<class T> struct pointer_traits<T*> {
+    static pointer pointer_to(element_type& v);
+};
+
+template<class T>
+struct pointer_traits<T*> {
     typedef T* pointer;
     typedef T element_type;
     typedef std::ptrdiff_t difference_type;
 
-    template<class U> struct rebind_to { typedef U* type; };
-    template<class U> using rebind = typename rebind_to<U>::type;
+    template<class U>
+    struct rebind_to {
+        typedef U* type;
+    };
+
+    template<class U>
+    using rebind = typename rebind_to<U>::type;
 
     static pointer pointer_to(``['see below]`` v) noexcept;
-  };
+};
 
-  template<class T>
-  constexpr T* to_address(T* v) noexcept;
+template<class T>
+constexpr T* to_address(T* v) noexcept;
 
-  template<class T>
-  auto to_address(const T& v) noexcept;
-}
+template<class T>
+auto to_address(const T& v) noexcept;
+
+} // boost
 ```
 
+[section Overview]
+
+If the member type `element_type` is not defined, then all other members are
+also not defined (`pointer_traits` is SFINAE-friendly).
+
+[endsect]
+
 [section Member types]
 
 [variablelist
 [[`typedef` ['see below] `element_type;`]
 [`T::element_type` if such a type exists; otherwise `U` if `T` is a class
   template instantiation of the form `Pointer<U, Args>`, where `Args` is zero
-  or more type arguments; otherwise the specialization is ill-formed.]]
+  or more type arguments; otherwise the member is not defined.]]
 [[`typedef` ['see below] `difference_type;`]
 [`T::difference_type` if such a type exists; otherwise `std::ptrdiff_t`.]]
 [[`template<class U> struct rebind_to { typedef` ['see below] `type; };`]
 [`type` is `T::rebind<U>` if such a type exists; otherwise, `Pointer<V, Args>`
   if `T` is a class template instantiation of the form `Pointer<T, Args>`,
-  where `Args` is zero or more type arguments; otherwise, the instantiation of
-  `rebind_to` is ill-formed.]]]
+  where `Args` is zero or more type arguments; otherwise, the member is not
+  defined.]]]
 
 [endsect]
 
 [section Member functions]
 
 [variablelist
-[[`static pointer pointer_traits::pointer_to(`['see below] `v);`]
+[[`static pointer pointer_traits::pointer_to(element_type& v);`]
 [[variablelist
 [[Remark]
-[If `element_type` is a void type, the type of `v` is unspecified; otherwise,
-  it is `element_type&`.]]
+[If `element_type` is a void type, this member is not defined.]]
 [[Returns]
 [A pointer to `v` obtained by calling `T::pointer_to(v)`.]]]]]
-[[`static pointer pointer_traits<T*>::pointer_to(`['see below] `v) noexcept;`]
+[[`static pointer pointer_traits<T*>::pointer_to(element_type& v) noexcept;`]
 [[variablelist
 [[Remark]
-[If `element_type` is a void type, the type of `v` is unspecified; otherwise,
-  it is `element_type&`.]]
+[If `element_type` is a void type, this member is not defined.]]
 [[Returns][`addressof(v)`.]]]]]]
 
 [endsect]
diff --git a/include/boost/core/pointer_traits.hpp b/include/boost/core/pointer_traits.hpp
index e66194d..2e78598 100644
--- a/include/boost/core/pointer_traits.hpp
+++ b/include/boost/core/pointer_traits.hpp
@@ -1,5 +1,5 @@
 /*
-Copyright 2017-2018 Glen Joseph Fernandes
+Copyright 2017-2021 Glen Joseph Fernandes
 (glenjofe@gmail.com)
 
 Distributed under the Boost Software License, Version 1.0.
@@ -9,43 +9,23 @@ Distributed under the Boost Software License, Version 1.0.
 #define BOOST_CORE_POINTER_TRAITS_HPP
 
 #include <boost/config.hpp>
-#if !defined(BOOST_NO_CXX11_POINTER_TRAITS)
-#include <memory>
-#else
 #include <boost/core/addressof.hpp>
 #include <cstddef>
-#endif
 
 namespace boost {
-
-#if !defined(BOOST_NO_CXX11_POINTER_TRAITS)
-template<class T>
-struct pointer_traits
-    : std::pointer_traits<T> {
-    template<class U>
-    struct rebind_to {
-        typedef typename std::pointer_traits<T>::template rebind<U> type;
-    };
-};
-
-template<class T>
-struct pointer_traits<T*>
-    : std::pointer_traits<T*> {
-    template<class U>
-    struct rebind_to {
-        typedef U* type;
-    };
-};
-#else
 namespace detail {
 
+struct ptr_none { };
+
 template<class>
-struct ptr_void {
+struct ptr_valid {
     typedef void type;
 };
 
-template<class T>
-struct ptr_first;
+template<class>
+struct ptr_first {
+    typedef ptr_none type;
+};
 
 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
 template<template<class, class...> class T, class U, class... Args>
@@ -75,7 +55,7 @@ struct ptr_element {
 };
 
 template<class T>
-struct ptr_element<T, typename ptr_void<typename T::element_type>::type> {
+struct ptr_element<T, typename ptr_valid<typename T::element_type>::type> {
     typedef typename T::element_type type;
 };
 
@@ -86,12 +66,12 @@ struct ptr_difference {
 
 template<class T>
 struct ptr_difference<T,
-    typename ptr_void<typename T::difference_type>::type> {
+    typename ptr_valid<typename T::difference_type>::type> {
     typedef typename T::difference_type type;
 };
 
-template<class T, class V>
-struct ptr_transform;
+template<class, class>
+struct ptr_transform { };
 
 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
 template<template<class, class...> class T, class U, class... Args, class V>
@@ -117,68 +97,100 @@ struct ptr_transform<T<U1, U2, U3>, V> {
 #endif
 
 template<class T, class U, class = void>
-struct ptr_rebind {
-    typedef typename ptr_transform<T, U>::type type;
-};
+struct ptr_rebind
+    : ptr_transform<T, U> { };
 
-#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
 template<class T, class U>
 struct ptr_rebind<T, U,
-    typename ptr_void<typename T::template rebind<U> >::type> {
+    typename ptr_valid<typename T::template rebind<U> >::type> {
     typedef typename T::template rebind<U> type;
 };
-#endif
 
-template<class T>
-struct ptr_value {
-    typedef T type;
+template<class>
+struct ptr_void {
+    BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<>
-struct ptr_value<void> {
-    typedef struct { } type;
+struct ptr_void<void> {
+    BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
+template<>
+struct ptr_void<const void> {
+    BOOST_STATIC_CONSTEXPR bool value = true;
+};
+
+template<>
+struct ptr_void<volatile void> {
+    BOOST_STATIC_CONSTEXPR bool value = true;
+};
+
+template<>
+struct ptr_void<const volatile void> {
+    BOOST_STATIC_CONSTEXPR bool value = true;
+};
+
+template<class, class E, bool = ptr_void<E>::value>
+struct ptr_to { };
+
+template<class T, class E>
+struct ptr_to<T, E, false> {
+    static T pointer_to(E& v) {
+        return T::pointer_to(v);
+    }
+};
+
+template<class T>
+struct ptr_to<T*, T, false> {
+    static T* pointer_to(T& v) BOOST_NOEXCEPT {
+        return boost::addressof(v);
+    }
+};
+
+template<class T, class E>
+struct ptr_traits
+    : ptr_to<T, E> {
+    typedef T pointer;
+    typedef E element_type;
+    typedef typename ptr_difference<T>::type difference_type;
+
+    template<class U>
+    struct rebind_to
+        : ptr_rebind<T, U> { };
+
+#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
+    template<class U>
+    using rebind = typename rebind_to<U>::type;
+#endif
+};
+
+template<class T>
+struct ptr_traits<T, ptr_none> { };
+
 } /* detail */
 
 template<class T>
-struct pointer_traits {
-    typedef T pointer;
-    typedef typename detail::ptr_element<T>::type element_type;
-    typedef typename detail::ptr_difference<T>::type difference_type;
-    template<class U>
-    struct rebind_to {
-        typedef typename detail::ptr_rebind<T, U>::type type;
-    };
-#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
-    template<class U>
-    using rebind = typename detail::ptr_rebind<T, U>::type;
-#endif
-    static pointer
-    pointer_to(typename detail::ptr_value<element_type>::type& v) {
-        return pointer::pointer_to(v);
-    }
-};
+struct pointer_traits
+    : detail::ptr_traits<T, typename detail::ptr_element<T>::type> { };
 
 template<class T>
-struct pointer_traits<T*> {
+struct pointer_traits<T*>
+    : detail::ptr_to<T*, T> {
     typedef T* pointer;
     typedef T element_type;
     typedef std::ptrdiff_t difference_type;
+
     template<class U>
     struct rebind_to {
         typedef U* type;
     };
+
 #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
     template<class U>
-    using rebind = U*;
+    using rebind = typename rebind_to<U>::type*;
 #endif
-    static T*
-    pointer_to(typename detail::ptr_value<T>::type& v) BOOST_NOEXCEPT {
-        return boost::addressof(v);
-    }
 };
-#endif
 
 template<class T>
 BOOST_CONSTEXPR inline T*
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 58d46f5..9be78c0 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -189,6 +189,9 @@ run pointer_traits_element_type_test.cpp ;
 run pointer_traits_difference_type_test.cpp ;
 run pointer_traits_rebind_test.cpp ;
 run pointer_traits_pointer_to_test.cpp ;
+run pointer_traits_sfinae_test.cpp ;
+run pointer_traits_rebind_sfinae_test.cpp ;
+run pointer_traits_pointer_to_sfinae_test.cpp ;
 run to_address_test.cpp ;
 
 run exchange_test.cpp ;
diff --git a/test/pointer_traits_pointer_to_sfinae_test.cpp b/test/pointer_traits_pointer_to_sfinae_test.cpp
new file mode 100644
index 0000000..30f6cec
--- /dev/null
+++ b/test/pointer_traits_pointer_to_sfinae_test.cpp
@@ -0,0 +1,75 @@
+/*
+Copyright 2021 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/config.hpp>
+#if !defined(BOOST_NO_CXX11_DECLTYPE_N3276) || !defined(BOOST_MSVC)
+#include <boost/core/pointer_traits.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
+template<class T>
+class has_pointer_to {
+    template<class>
+    struct result {
+        char one;
+        char two;
+    };
+
+    template<class O>
+    static auto check(int) -> result<decltype(O::pointer_to)>;
+
+    template<class O>
+    static char check(long);
+
+public:
+    static const bool value = sizeof(check<T>(0)) != 1;
+};
+#else
+template<class T>
+class has_pointer_to {
+    template<int>
+    struct result {
+        char one;
+        char two;
+    };
+
+    template<class O>
+    static result<sizeof(&O::pointer_to)> check(int);
+
+    template<class>
+    static char check(long);
+
+public:
+    static const bool value = sizeof(check<T>(0)) != 1;
+};
+#endif
+
+struct P1 { };
+
+struct P2 {
+    typedef int element_type;
+};
+
+struct P3 {
+    typedef void element_type;
+};
+
+int main()
+{
+    BOOST_TEST((!has_pointer_to<boost::pointer_traits<P1> >::value));
+    BOOST_TEST(has_pointer_to<boost::pointer_traits<P2> >::value);
+    BOOST_TEST(!has_pointer_to<boost::pointer_traits<P3> >::value);
+    BOOST_TEST(has_pointer_to<boost::pointer_traits<int*> >::value);
+    BOOST_TEST(!has_pointer_to<boost::pointer_traits<void*> >::value);
+    return boost::report_errors();
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif
diff --git a/test/pointer_traits_rebind_sfinae_test.cpp b/test/pointer_traits_rebind_sfinae_test.cpp
new file mode 100644
index 0000000..d6ad087
--- /dev/null
+++ b/test/pointer_traits_rebind_sfinae_test.cpp
@@ -0,0 +1,83 @@
+/*
+Copyright 2021 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/config.hpp>
+#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) && \
+    (!defined(BOOST_GCC) || (BOOST_GCC >= 40800)) && \
+    (!defined(BOOST_MSVC) || (BOOST_MSVC >= 1900))
+#include <boost/core/pointer_traits.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+template<class>
+struct valid {
+    typedef void type;
+};
+
+#if !defined(BOOST_GCC) || (BOOST_GCC >= 50000)
+template<class, class, class = void>
+struct has_rebind {
+    static const bool value = false;
+};
+
+template<class T, class U>
+struct has_rebind<T, U,
+    typename valid<typename T::template rebind<U> >::type> {
+    static const bool value = true;
+};
+#else
+template<template<class> class T, class U>
+using defer = T<U>;
+
+template<class T, class U>
+using rebind = defer<T::template rebind, U>;
+
+template<class, class, template<class, class> class = rebind, class = void>
+struct has_rebind {
+    static const bool value = false;
+};
+
+template<class T, class U, template<class, class> class R>
+struct has_rebind<T, U, R, typename valid<R<T, U> >::type> {
+    static const bool value = true;
+};
+#endif
+
+struct P1 { };
+
+struct P2 {
+    typedef int element_type;
+};
+
+struct P3 {
+    typedef int element_type;
+
+    template<class>
+    struct rebind { };
+};
+
+template<class T>
+struct S {
+    typedef T element_type;
+};
+
+typedef S<int> P4;
+
+int main()
+{
+    BOOST_TEST((!has_rebind<boost::pointer_traits<P1>, char>::value));
+    BOOST_TEST((!has_rebind<boost::pointer_traits<P2>, char>::value));
+    BOOST_TEST((has_rebind<boost::pointer_traits<P3>, char>::value));
+    BOOST_TEST((has_rebind<boost::pointer_traits<P4>, char>::value));
+    BOOST_TEST((has_rebind<boost::pointer_traits<int*>, char>::value));
+    return boost::report_errors();
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif
diff --git a/test/pointer_traits_sfinae_test.cpp b/test/pointer_traits_sfinae_test.cpp
new file mode 100644
index 0000000..a7ae787
--- /dev/null
+++ b/test/pointer_traits_sfinae_test.cpp
@@ -0,0 +1,101 @@
+/*
+Copyright 2021 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/core/pointer_traits.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+template<class>
+struct valid {
+    typedef void type;
+};
+
+template<class, class = void>
+struct has_pointer {
+    static const bool value = false;
+};
+
+template<class T>
+struct has_pointer<T, typename valid<typename T::pointer>::type> {
+    static const bool value = true;
+};
+
+template<class, class = void>
+struct has_element_type {
+    static const bool value = false;
+};
+
+template<class T>
+struct has_element_type<T, typename valid<typename T::element_type>::type> {
+    static const bool value = true;
+};
+
+template<class, class = void>
+struct has_difference_type {
+    static const bool value = false;
+};
+
+template<class T>
+struct has_difference_type<T,
+    typename valid<typename T::difference_type>::type> {
+    static const bool value = true;
+};
+
+template<class, class, class = void>
+struct has_rebind_to_type {
+    static const bool value = false;
+};
+
+template<class T, class U>
+struct has_rebind_to_type<T, U,
+    typename valid<typename T::template rebind_to<U>::type>::type> {
+    static const bool value = true;
+};
+
+struct P1 { };
+
+struct P2 {
+    typedef int element_type;
+};
+
+struct P3 {
+    typedef int element_type;
+
+    template<class>
+    struct rebind { };
+};
+
+template<class T>
+struct S {
+    typedef T element_type;
+};
+
+typedef S<int> P4;
+
+int main()
+{
+    BOOST_TEST(!has_pointer<boost::pointer_traits<P1> >::value);
+    BOOST_TEST(!has_element_type<boost::pointer_traits<P1> >::value);
+    BOOST_TEST(!has_difference_type<boost::pointer_traits<P1> >::value);
+    BOOST_TEST((!has_rebind_to_type<boost::pointer_traits<P1>, char>::value));
+    BOOST_TEST(has_pointer<boost::pointer_traits<P2> >::value);
+    BOOST_TEST(has_element_type<boost::pointer_traits<P2> >::value);
+    BOOST_TEST(has_difference_type<boost::pointer_traits<P2> >::value);
+    BOOST_TEST((!has_rebind_to_type<boost::pointer_traits<P2>, char>::value));
+    BOOST_TEST(has_pointer<boost::pointer_traits<P3> >::value);
+    BOOST_TEST(has_element_type<boost::pointer_traits<P3> >::value);
+    BOOST_TEST(has_difference_type<boost::pointer_traits<P3> >::value);
+    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<P3>, char>::value));
+    BOOST_TEST(has_pointer<boost::pointer_traits<P4> >::value);
+    BOOST_TEST(has_element_type<boost::pointer_traits<P4> >::value);
+    BOOST_TEST(has_difference_type<boost::pointer_traits<P4> >::value);
+    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<P4>, char>::value));
+    BOOST_TEST(has_pointer<boost::pointer_traits<int*> >::value);
+    BOOST_TEST(has_element_type<boost::pointer_traits<int*> >::value);
+    BOOST_TEST(has_difference_type<boost::pointer_traits<int*> >::value);
+    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<int*>, char>::value));
+    return boost::report_errors();
+}
diff --git a/test/to_address_test.cpp b/test/to_address_test.cpp
index 4c02384..4662e32 100644
--- a/test/to_address_test.cpp
+++ b/test/to_address_test.cpp
@@ -13,9 +13,11 @@ class P1 {
 public:
     explicit P1(T* p)
         : p_(p) { }
+
     T* operator->() const BOOST_NOEXCEPT {
         return p_;
     }
+
 private:
     T* p_;
 };
@@ -25,9 +27,11 @@ class P2 {
 public:
     explicit P2(T* p)
         : p_(p) { }
+
     P1<T> operator->() const BOOST_NOEXCEPT {
         return p_;
     }
+
 private:
     P1<T> p_;
 };
@@ -38,20 +42,24 @@ class P3 {
 public:
     explicit P3(T* p)
         : p_(p) { }
+
     T* get() const BOOST_NOEXCEPT {
         return p_;
     }
+
 private:
     T* p_;
 };
 
 namespace boost {
+
 template<class T>
 struct pointer_traits<P3<T> > {
     static T* to_address(const P3<T>& p) BOOST_NOEXCEPT {
         return p.get();
     }
 };
+
 } /* boost */
 
 template<class T>
@@ -59,77 +67,29 @@ class P4 {
 public:
     explicit P4(T* p)
         : p_(p) { }
+
     T* operator->() const BOOST_NOEXCEPT {
         return 0;
     }
+
     T* get() const BOOST_NOEXCEPT {
         return p_;
     }
+
 private:
     int* p_;
 };
 
 namespace boost {
+
 template<class T>
 struct pointer_traits<P4<T> > {
     static T* to_address(const P4<T>& p) BOOST_NOEXCEPT {
         return p.get();
     }
 };
+
 } /* boost */
-
-#if !defined(BOOST_NO_CXX11_POINTER_TRAITS)
-template<class T>
-class P5 {
-public:
-    explicit P5(T* p)
-        : p_(p) { }
-    T* get() const BOOST_NOEXCEPT {
-        return p_;
-    }
-private:
-    T* p_;
-};
-
-namespace std {
-template<class T>
-struct pointer_traits<P5<T> > {
-    static T* to_address(const P5<T>& p) BOOST_NOEXCEPT {
-        return p.get();
-    }
-};
-} /* std */
-
-template<class T>
-class P6 {
-public:
-    explicit P6(T* p)
-        : p_(p) { }
-    T* get() const BOOST_NOEXCEPT {
-        return p_;
-    }
-private:
-    T* p_;
-};
-
-namespace boost {
-template<class T>
-struct pointer_traits<P6<T> > {
-    static T* to_address(const P6<T>& p) BOOST_NOEXCEPT {
-        return p.get();
-    }
-};
-} /* boost */
-
-namespace std {
-template<class T>
-struct pointer_traits<P6<T> > {
-    static T* to_address(const P6<T>& /*p*/) BOOST_NOEXCEPT {
-        return 0;
-    }
-};
-} /* std */
-#endif
 #endif
 
 int main()
@@ -147,12 +107,6 @@ int main()
     BOOST_TEST(boost::to_address(p3) == &i);
     P4<int> p4(&i);
     BOOST_TEST(boost::to_address(p4) == &i);
-#if !defined(BOOST_NO_CXX11_POINTER_TRAITS)
-    P5<int> p5(&i);
-    BOOST_TEST(boost::to_address(p5) == &i);
-    P6<int> p6(&i);
-    BOOST_TEST(boost::to_address(p6) == &i);
-#endif
 #endif
     return boost::report_errors();
 }