diff --git a/include/boost/smart_ptr/detail/operator_bool.hpp b/include/boost/smart_ptr/detail/operator_bool.hpp
new file mode 100644
index 0000000..842a05d
--- /dev/null
+++ b/include/boost/smart_ptr/detail/operator_bool.hpp
@@ -0,0 +1,56 @@
+//  This header intentionally has no include guards.
+//
+//  Copyright (c) 2001-2009 Peter Dimov
+//
+//  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
+
+#if ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)
+
+    operator bool () const
+    {
+        return px != 0;
+    }
+
+#elif defined( _MANAGED )
+
+    static void unspecified_bool( this_type*** )
+    {
+    }
+
+    typedef void (*unspecified_bool_type)( this_type*** );
+
+    operator unspecified_bool_type() const // never throws
+    {
+        return px == 0? 0: unspecified_bool;
+    }
+
+#elif \
+    ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \
+    ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) ) || \
+    ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) )
+
+    typedef T * (this_type::*unspecified_bool_type)() const;
+
+    operator unspecified_bool_type() const // never throws
+    {
+        return px == 0? 0: &this_type::get;
+    }
+
+#else
+
+    typedef T * this_type::*unspecified_bool_type;
+
+    operator unspecified_bool_type() const // never throws
+    {
+        return px == 0? 0: &this_type::px;
+    }
+
+#endif
+
+    // operator! is redundant, but some compilers need it
+    bool operator! () const // never throws
+    {
+        return px == 0;
+    }
diff --git a/include/boost/smart_ptr/intrusive_ptr.hpp b/include/boost/smart_ptr/intrusive_ptr.hpp
index f5acae3..d3bd02b 100644
--- a/include/boost/smart_ptr/intrusive_ptr.hpp
+++ b/include/boost/smart_ptr/intrusive_ptr.hpp
@@ -63,13 +63,13 @@ public:
 
     typedef T element_type;
 
-    intrusive_ptr(): p_(0)
+    intrusive_ptr(): px( 0 )
     {
     }
 
-    intrusive_ptr(T * p, bool add_ref = true): p_(p)
+    intrusive_ptr( T * p, bool add_ref = true ): px( p )
     {
-        if(p_ != 0 && add_ref) intrusive_ptr_add_ref(p_);
+        if( px != 0 && add_ref ) intrusive_ptr_add_ref( px );
     }
 
 #if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
@@ -84,21 +84,21 @@ public:
     intrusive_ptr( intrusive_ptr<U> const & rhs )
 
 #endif
-    : p_( rhs.get() )
+    : px( rhs.get() )
     {
-        if( p_ != 0 ) intrusive_ptr_add_ref( p_ );
+        if( px != 0 ) intrusive_ptr_add_ref( px );
     }
 
 #endif
 
-    intrusive_ptr(intrusive_ptr const & rhs): p_(rhs.p_)
+    intrusive_ptr(intrusive_ptr const & rhs): px( rhs.px )
     {
-        if(p_ != 0) intrusive_ptr_add_ref(p_);
+        if( px != 0 ) intrusive_ptr_add_ref( px );
     }
 
     ~intrusive_ptr()
     {
-        if(p_ != 0) intrusive_ptr_release(p_);
+        if( px != 0 ) intrusive_ptr_release( px );
     }
 
 #if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
@@ -135,63 +135,34 @@ public:
 
     T * get() const
     {
-        return p_;
+        return px;
     }
 
     T & operator*() const
     {
-        BOOST_ASSERT( p_ != 0 );
-        return *p_;
+        BOOST_ASSERT( px != 0 );
+        return *px;
     }
 
     T * operator->() const
     {
-        BOOST_ASSERT( p_ != 0 );
-        return p_;
+        BOOST_ASSERT( px != 0 );
+        return px;
     }
 
-#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
-
-    operator bool () const
-    {
-        return p_ != 0;
-    }
-
-#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
-    typedef T * (this_type::*unspecified_bool_type)() const;
-    
-    operator unspecified_bool_type() const // never throws
-    {
-        return p_ == 0? 0: &this_type::get;
-    }
-
-#else 
-
-    typedef T * this_type::*unspecified_bool_type;
-
-    operator unspecified_bool_type () const
-    {
-        return p_ == 0? 0: &this_type::p_;
-    }
-
-#endif
-
-    // operator! is a Borland-specific workaround
-    bool operator! () const
-    {
-        return p_ == 0;
-    }
+// implicit conversion to "bool"
+#include <boost/smart_ptr/detail/operator_bool.hpp>
 
     void swap(intrusive_ptr & rhs)
     {
-        T * tmp = p_;
-        p_ = rhs.p_;
-        rhs.p_ = tmp;
+        T * tmp = px;
+        px = rhs.px;
+        rhs.px = tmp;
     }
 
 private:
 
-    T * p_;
+    T * px;
 };
 
 template<class T, class U> inline bool operator==(intrusive_ptr<T> const & a, intrusive_ptr<U> const & b)
diff --git a/include/boost/smart_ptr/scoped_array.hpp b/include/boost/smart_ptr/scoped_array.hpp
index 23c2f87..483460f 100644
--- a/include/boost/smart_ptr/scoped_array.hpp
+++ b/include/boost/smart_ptr/scoped_array.hpp
@@ -39,7 +39,7 @@ template<class T> class scoped_array // noncopyable
 {
 private:
 
-    T * ptr;
+    T * px;
 
     scoped_array(scoped_array const &);
     scoped_array & operator=(scoped_array const &);
@@ -53,79 +53,48 @@ public:
 
     typedef T element_type;
 
-    explicit scoped_array(T * p = 0) : ptr(p) // never throws
+    explicit scoped_array( T * p = 0 ) : px( p ) // never throws
     {
 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
-        boost::sp_array_constructor_hook(ptr);
+        boost::sp_array_constructor_hook( px );
 #endif
     }
 
     ~scoped_array() // never throws
     {
 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
-        boost::sp_array_destructor_hook(ptr);
+        boost::sp_array_destructor_hook( px );
 #endif
-        boost::checked_array_delete(ptr);
+        boost::checked_array_delete( px );
     }
 
     void reset(T * p = 0) // never throws
     {
-        BOOST_ASSERT(p == 0 || p != ptr); // catch self-reset errors
+        BOOST_ASSERT( p == 0 || p != px ); // catch self-reset errors
         this_type(p).swap(*this);
     }
 
     T & operator[](std::ptrdiff_t i) const // never throws
     {
-        BOOST_ASSERT(ptr != 0);
-        BOOST_ASSERT(i >= 0);
-        return ptr[i];
+        BOOST_ASSERT( px != 0 );
+        BOOST_ASSERT( i >= 0 );
+        return px[i];
     }
 
     T * get() const // never throws
     {
-        return ptr;
+        return px;
     }
 
-    // implicit conversion to "bool"
-
-#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
-
-    operator bool () const
-    {
-        return ptr != 0;
-    }
-
-#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
-    typedef T * (this_type::*unspecified_bool_type)() const;
-    
-    operator unspecified_bool_type() const // never throws
-    {
-        return ptr == 0? 0: &this_type::get;
-    }
-
-#else 
-
-    typedef T * this_type::*unspecified_bool_type;
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return ptr == 0? 0: &this_type::ptr;
-    }
-
-#endif
-
-    bool operator! () const // never throws
-    {
-        return ptr == 0;
-    }
+// implicit conversion to "bool"
+#include <boost/smart_ptr/detail/operator_bool.hpp>
 
     void swap(scoped_array & b) // never throws
     {
-        T * tmp = b.ptr;
-        b.ptr = ptr;
-        ptr = tmp;
+        T * tmp = b.px;
+        b.px = px;
+        px = tmp;
     }
-
 };
 
 template<class T> inline void swap(scoped_array<T> & a, scoped_array<T> & b) // never throws
diff --git a/include/boost/smart_ptr/scoped_ptr.hpp b/include/boost/smart_ptr/scoped_ptr.hpp
index 518a254..df479e5 100644
--- a/include/boost/smart_ptr/scoped_ptr.hpp
+++ b/include/boost/smart_ptr/scoped_ptr.hpp
@@ -40,7 +40,7 @@ template<class T> class scoped_ptr // noncopyable
 {
 private:
 
-    T * ptr;
+    T * px;
 
     scoped_ptr(scoped_ptr const &);
     scoped_ptr & operator=(scoped_ptr const &);
@@ -54,19 +54,19 @@ public:
 
     typedef T element_type;
 
-    explicit scoped_ptr(T * p = 0): ptr(p) // never throws
+    explicit scoped_ptr( T * p = 0 ): px( p ) // never throws
     {
 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
-        boost::sp_scalar_constructor_hook(ptr);
+        boost::sp_scalar_constructor_hook( px );
 #endif
     }
 
 #ifndef BOOST_NO_AUTO_PTR
 
-    explicit scoped_ptr(std::auto_ptr<T> p): ptr(p.release()) // never throws
+    explicit scoped_ptr( std::auto_ptr<T> p ): px( p.release() ) // never throws
     {
 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
-        boost::sp_scalar_constructor_hook(ptr);
+        boost::sp_scalar_constructor_hook( px );
 #endif
     }
 
@@ -75,71 +75,42 @@ public:
     ~scoped_ptr() // never throws
     {
 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
-        boost::sp_scalar_destructor_hook(ptr);
+        boost::sp_scalar_destructor_hook( px );
 #endif
-        boost::checked_delete(ptr);
+        boost::checked_delete( px );
     }
 
     void reset(T * p = 0) // never throws
     {
-        BOOST_ASSERT(p == 0 || p != ptr); // catch self-reset errors
+        BOOST_ASSERT( p == 0 || p != px ); // catch self-reset errors
         this_type(p).swap(*this);
     }
 
     T & operator*() const // never throws
     {
-        BOOST_ASSERT(ptr != 0);
-        return *ptr;
+        BOOST_ASSERT( px != 0 );
+        return *px;
     }
 
     T * operator->() const // never throws
     {
-        BOOST_ASSERT(ptr != 0);
-        return ptr;
+        BOOST_ASSERT( px != 0 );
+        return px;
     }
 
     T * get() const // never throws
     {
-        return ptr;
+        return px;
     }
 
-    // implicit conversion to "bool"
-
-#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
-
-    operator bool () const
-    {
-        return ptr != 0;
-    }
-
-#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
-    typedef T * (this_type::*unspecified_bool_type)() const;
-    
-    operator unspecified_bool_type() const // never throws
-    {
-        return ptr == 0? 0: &this_type::get;
-    }
-
-#else 
-    typedef T * this_type::*unspecified_bool_type;
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return ptr == 0? 0: &this_type::ptr;
-    }
-
-#endif
-
-    bool operator! () const // never throws
-    {
-        return ptr == 0;
-    }
+// implicit conversion to "bool"
+#include <boost/smart_ptr/detail/operator_bool.hpp>
 
     void swap(scoped_ptr & b) // never throws
     {
-        T * tmp = b.ptr;
-        b.ptr = ptr;
-        ptr = tmp;
+        T * tmp = b.px;
+        b.px = px;
+        px = tmp;
     }
 };
 
diff --git a/include/boost/smart_ptr/shared_array.hpp b/include/boost/smart_ptr/shared_array.hpp
index 7d68aa2..1f50403 100644
--- a/include/boost/smart_ptr/shared_array.hpp
+++ b/include/boost/smart_ptr/shared_array.hpp
@@ -94,54 +94,8 @@ public:
         return px;
     }
 
-    // implicit conversion to "bool"
-
-#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
-
-    operator bool () const
-    {
-        return px != 0;
-    }
-
-#elif defined( _MANAGED )
-
-    static void unspecified_bool( this_type*** )
-    {
-    }
-
-    typedef void (*unspecified_bool_type)( this_type*** );
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: unspecified_bool;
-    }
-
-#elif \
-    ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \
-    ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) )
-
-    typedef T * (this_type::*unspecified_bool_type)() const;
-    
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: &this_type::get;
-    }
-
-#else 
-
-    typedef T * this_type::*unspecified_bool_type;
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: &this_type::px;
-    }
-
-#endif
-
-    bool operator! () const // never throws
-    {
-        return px == 0;
-    }
+// implicit conversion to "bool"
+#include <boost/smart_ptr/detail/operator_bool.hpp>
 
     bool unique() const // never throws
     {
diff --git a/include/boost/smart_ptr/shared_ptr.hpp b/include/boost/smart_ptr/shared_ptr.hpp
index 78711ed..c7cdaf7 100644
--- a/include/boost/smart_ptr/shared_ptr.hpp
+++ b/include/boost/smart_ptr/shared_ptr.hpp
@@ -425,57 +425,8 @@ public:
         return px;
     }
 
-    // implicit conversion to "bool"
-
-#if ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)
-
-    operator bool () const
-    {
-        return px != 0;
-    }
-
-#elif defined( _MANAGED )
-
-    static void unspecified_bool( this_type*** )
-    {
-    }
-
-    typedef void (*unspecified_bool_type)( this_type*** );
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: unspecified_bool;
-    }
-
-#elif \
-    ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \
-    ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) ) || \
-    ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) )
-
-    typedef T * (this_type::*unspecified_bool_type)() const;
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: &this_type::get;
-    }
-
-#else
-
-    typedef T * this_type::*unspecified_bool_type;
-
-    operator unspecified_bool_type() const // never throws
-    {
-        return px == 0? 0: &this_type::px;
-    }
-
-#endif
-
-    // operator! is redundant, but some compilers need it
-
-    bool operator! () const // never throws
-    {
-        return px == 0;
-    }
+// implicit conversion to "bool"
+#include <boost/smart_ptr/detail/operator_bool.hpp>
 
     bool unique() const // never throws
     {