diff --git a/include/boost/optional/detail/old_optional_implementation.hpp b/include/boost/optional/detail/old_optional_implementation.hpp
index 16dee20..62c31ee 100644
--- a/include/boost/optional/detail/old_optional_implementation.hpp
+++ b/include/boost/optional/detail/old_optional_implementation.hpp
@@ -730,7 +730,7 @@ class optional : public optional_detail::optional_base<T>
   explicit optional ( Expr&& expr, 
                       BOOST_DEDUCED_TYPENAME boost::disable_if_c<
                         (boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value) || 
-                        boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value >::type* = 0 
+                        boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value, bool >::type = true 
   ) 
     : base(boost::forward<Expr>(expr),boost::addressof(expr)) 
     {optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>();}
diff --git a/include/boost/optional/detail/optional_reference_spec.hpp b/include/boost/optional/detail/optional_reference_spec.hpp
index ce55875..012e91a 100644
--- a/include/boost/optional/detail/optional_reference_spec.hpp
+++ b/include/boost/optional/detail/optional_reference_spec.hpp
@@ -132,11 +132,11 @@ public:
     
     // the following two implement a 'conditionally explicit' constructor: condition is a hack for buggy compilers with srewed conversion construction from const int
     template <class U>
-      explicit optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value>::type* = 0) BOOST_NOEXCEPT
+      explicit optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value, bool>::type = true) BOOST_NOEXCEPT
       : ptr_(boost::addressof(rhs)) {}
       
     template <class U>
-      optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value>::type* = 0) BOOST_NOEXCEPT
+      optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value, bool>::type = true) BOOST_NOEXCEPT
       : ptr_(boost::addressof(rhs)) {}
 
     optional& operator=(const optional& rhs) BOOST_NOEXCEPT { ptr_ = rhs.get_ptr(); return *this; }
@@ -165,11 +165,11 @@ public:
     optional(T&& /* rhs */) BOOST_NOEXCEPT { detail::prevent_binding_rvalue<T&&>(); }
     
     template <class R>
-        optional(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::no_unboxing_cond<T, R> >::type* = 0) BOOST_NOEXCEPT
+        optional(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::no_unboxing_cond<T, R>, bool>::type = true) BOOST_NOEXCEPT
         : ptr_(boost::addressof(r)) { detail::prevent_binding_rvalue<R>(); }
         
     template <class R>
-        optional(bool cond, R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) BOOST_NOEXCEPT
+        optional(bool cond, R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R>, bool>::type = true) BOOST_NOEXCEPT
         : ptr_(cond ? boost::addressof(r) : 0) { detail::prevent_binding_rvalue<R>(); }
         
     template <class R>
@@ -177,19 +177,19 @@ public:
         operator=(R&& r) BOOST_NOEXCEPT { detail::prevent_binding_rvalue<R>(); ptr_ = boost::addressof(r); return *this; }
         
     template <class R>
-        void emplace(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) BOOST_NOEXCEPT
+        void emplace(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R>, bool>::type = true) BOOST_NOEXCEPT
         { detail::prevent_binding_rvalue<R>(); ptr_ = boost::addressof(r); }
         
     template <class R>
-      T& get_value_or(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) const BOOST_NOEXCEPT
+      T& get_value_or(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R>, bool>::type = true) const BOOST_NOEXCEPT
       { detail::prevent_binding_rvalue<R>(); return ptr_ ? *ptr_ : r; }
       
     template <class R>
-        T& value_or(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) const BOOST_NOEXCEPT
+        T& value_or(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R>, bool>::type = true) const BOOST_NOEXCEPT
         { detail::prevent_binding_rvalue<R>(); return ptr_ ? *ptr_ : r; }
         
     template <class R>
-      void reset(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) BOOST_NOEXCEPT
+      void reset(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R>, bool>::type = true) BOOST_NOEXCEPT
       { detail::prevent_binding_rvalue<R>(); ptr_ = boost::addressof(r); }
       
     template <class F>
@@ -200,15 +200,15 @@ public:
     
     // the following two implement a 'conditionally explicit' constructor
     template <class U>
-      explicit optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value >::type* = 0) BOOST_NOEXCEPT
+      explicit optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value, bool>::type = true) BOOST_NOEXCEPT
       : ptr_(boost::addressof(v)) { }
       
     template <class U>
-      optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value >::type* = 0) BOOST_NOEXCEPT
+      optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value, bool>::type = true) BOOST_NOEXCEPT
       : ptr_(boost::addressof(v)) { }
         
     template <class U>
-      optional(bool cond, U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT : ptr_(cond ? boost::addressof(v) : 0) {}
+      optional(bool cond, U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, bool>::type = true) BOOST_NOEXCEPT : ptr_(cond ? boost::addressof(v) : 0) {}
 
     template <class U>
       BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, optional<T&>&>::type
@@ -219,19 +219,19 @@ public:
       }
 
     template <class U>
-        void emplace(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT
+        void emplace(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, bool>::type = true) BOOST_NOEXCEPT
         { ptr_ = boost::addressof(v); }
         
     template <class U>
-      T& get_value_or(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) const BOOST_NOEXCEPT
+      T& get_value_or(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, bool>::type = true) const BOOST_NOEXCEPT
       { return ptr_ ? *ptr_ : v; }
       
     template <class U>
-        T& value_or(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) const BOOST_NOEXCEPT
+        T& value_or(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, bool>::type = true) const BOOST_NOEXCEPT
         { return ptr_ ? *ptr_ : v; }
         
     template <class U>
-      void reset(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT
+      void reset(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, bool>::type = true) BOOST_NOEXCEPT
       { ptr_ = boost::addressof(v); }
       
     template <class F>
diff --git a/include/boost/optional/optional.hpp b/include/boost/optional/optional.hpp
index ecf686e..74ef49c 100644
--- a/include/boost/optional/optional.hpp
+++ b/include/boost/optional/optional.hpp
@@ -884,7 +884,7 @@ class optional
     template<class U>
     explicit optional ( optional<U> const& rhs
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
-                        ,typename boost::enable_if< optional_detail::is_optional_constructible<T, U const&> >::type* = 0
+                        ,BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_constructible<T, U const&>, bool>::type = true
 #endif
                       )
       :
@@ -901,7 +901,7 @@ class optional
     template<class U>
     explicit optional ( optional<U> && rhs
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
-                        ,typename boost::enable_if< optional_detail::is_optional_constructible<T, U> >::type* = 0
+                        ,BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_constructible<T, U>, bool>::type = true
 #endif
                       )
       :
@@ -927,7 +927,7 @@ class optional
 
   template<class Expr>
   explicit optional ( Expr&& expr, 
-                      BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_val_init_candidate<T, Expr> >::type* = 0 
+                      BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_val_init_candidate<T, Expr>, bool>::type = true 
   ) 
     : base(boost::forward<Expr>(expr),boost::addressof(expr)) 
     {}