imgtools/imglib/boostlibrary/boost/function/function_base.hpp
changeset 0 044383f39525
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/imgtools/imglib/boostlibrary/boost/function/function_base.hpp	Tue Oct 27 16:36:35 2009 +0000
@@ -0,0 +1,880 @@
+// Boost.Function library
+
+//  Copyright Douglas Gregor 2001-2006
+//  Copyright Emil Dotchevski 2007
+//  Use, modification and distribution is subject to 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)
+
+// For more information, see http://www.boost.org
+
+#ifndef BOOST_FUNCTION_BASE_HEADER
+#define BOOST_FUNCTION_BASE_HEADER
+
+#include <stdexcept>
+#include <string>
+#include <memory>
+#include <new>
+#include <typeinfo>
+#include <boost/config.hpp>
+#include <boost/assert.hpp>
+#include <boost/type_traits/is_const.hpp>
+#include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/is_volatile.hpp>
+#include <boost/type_traits/composite_traits.hpp>
+#include <boost/type_traits/ice.hpp>
+#include <boost/ref.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/detail/workaround.hpp>
+#include <boost/type_traits/alignment_of.hpp>
+#ifndef BOOST_NO_SFINAE
+#  include "boost/utility/enable_if.hpp"
+#else
+#  include "boost/mpl/bool.hpp"
+#endif
+#include <boost/function_equal.hpp>
+#include <boost/function/function_fwd.hpp>
+
+#if defined(BOOST_MSVC)
+#   pragma warning( push )
+#   pragma warning( disable : 4793 ) // complaint about native code generation
+#   pragma warning( disable : 4127 ) // "conditional expression is constant"
+#endif       
+
+// Define BOOST_FUNCTION_STD_NS to the namespace that contains type_info.
+#ifdef BOOST_NO_EXCEPTION_STD_NAMESPACE
+// Embedded VC++ does not have type_info in namespace std
+#  define BOOST_FUNCTION_STD_NS
+#else
+#  define BOOST_FUNCTION_STD_NS std
+#endif
+
+// Borrowed from Boost.Python library: determines the cases where we
+// need to use std::type_info::name to compare instead of operator==.
+# if (defined(__GNUC__) && __GNUC__ >= 3) \
+ || defined(_AIX) \
+ || (   defined(__sgi) && defined(__host_mips))
+#  include <cstring>
+#  define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) \
+     (std::strcmp((X).name(),(Y).name()) == 0)
+# else
+#  define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) ((X)==(Y))
+#endif
+
+#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 || defined(__ICL) && __ICL <= 600 || defined(__MWERKS__) && __MWERKS__ < 0x2406 && !defined(BOOST_STRICT_CONFIG)
+#  define BOOST_FUNCTION_TARGET_FIX(x) x
+#else
+#  define BOOST_FUNCTION_TARGET_FIX(x)
+#endif // not MSVC
+
+#if !BOOST_WORKAROUND(__BORLANDC__, < 0x5A0)
+#  define BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor,Type)              \
+      typename ::boost::enable_if_c<(::boost::type_traits::ice_not<          \
+                            (::boost::is_integral<Functor>::value)>::value), \
+                           Type>::type
+#else
+// BCC doesn't recognize this depends on a template argument and complains
+// about the use of 'typename'
+#  define BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor,Type)     \
+      ::boost::enable_if_c<(::boost::type_traits::ice_not<          \
+                   (::boost::is_integral<Functor>::value)>::value), \
+                       Type>::type
+#endif
+
+namespace boost {
+  namespace detail {
+    namespace function {
+      class X;
+
+      /**
+       * A buffer used to store small function objects in
+       * boost::function. It is a union containing function pointers,
+       * object pointers, and a structure that resembles a bound
+       * member function pointer.
+       */
+      union function_buffer
+      {
+        // For pointers to function objects
+        mutable void* obj_ptr;
+
+        // For pointers to std::type_info objects
+        struct type_t {
+          // (get_functor_type_tag, check_functor_type_tag).
+          const BOOST_FUNCTION_STD_NS::type_info* type;
+
+          // Whether the type is const-qualified.
+          bool const_qualified;
+          // Whether the type is volatile-qualified.
+          bool volatile_qualified;
+        } type;
+
+        // For function pointers of all kinds
+        mutable void (*func_ptr)();
+
+        // For bound member pointers
+        struct bound_memfunc_ptr_t {
+          void (X::*memfunc_ptr)(int);
+          void* obj_ptr;
+        } bound_memfunc_ptr;
+
+        // For references to function objects. We explicitly keep
+        // track of the cv-qualifiers on the object referenced.
+        struct obj_ref_t {
+          mutable void* obj_ptr;
+          bool is_const_qualified;
+          bool is_volatile_qualified;
+        } obj_ref;
+
+        // To relax aliasing constraints
+        mutable char data;
+      };
+
+      /**
+       * The unusable class is a placeholder for unused function arguments
+       * It is also completely unusable except that it constructable from
+       * anything. This helps compilers without partial specialization to
+       * handle Boost.Function objects returning void.
+       */
+      struct unusable
+      {
+        unusable() {}
+        template<typename T> unusable(const T&) {}
+      };
+
+      /* Determine the return type. This supports compilers that do not support
+       * void returns or partial specialization by silently changing the return
+       * type to "unusable".
+       */
+      template<typename T> struct function_return_type { typedef T type; };
+
+      template<>
+      struct function_return_type<void>
+      {
+        typedef unusable type;
+      };
+
+      // The operation type to perform on the given functor/function pointer
+      enum functor_manager_operation_type {
+        clone_functor_tag,
+        move_functor_tag,
+        destroy_functor_tag,
+        check_functor_type_tag,
+        get_functor_type_tag
+      };
+
+      // Tags used to decide between different types of functions
+      struct function_ptr_tag {};
+      struct function_obj_tag {};
+      struct member_ptr_tag {};
+      struct function_obj_ref_tag {};
+
+      template<typename F>
+      class get_function_tag
+      {
+        typedef typename mpl::if_c<(is_pointer<F>::value),
+                                   function_ptr_tag,
+                                   function_obj_tag>::type ptr_or_obj_tag;
+
+        typedef typename mpl::if_c<(is_member_pointer<F>::value),
+                                   member_ptr_tag,
+                                   ptr_or_obj_tag>::type ptr_or_obj_or_mem_tag;
+
+        typedef typename mpl::if_c<(is_reference_wrapper<F>::value),
+                                   function_obj_ref_tag,
+                                   ptr_or_obj_or_mem_tag>::type or_ref_tag;
+
+      public:
+        typedef or_ref_tag type;
+      };
+
+      // The trivial manager does nothing but return the same pointer (if we
+      // are cloning) or return the null pointer (if we are deleting).
+      template<typename F>
+      struct reference_manager
+      {
+        static inline void
+        manage(const function_buffer& in_buffer, function_buffer& out_buffer, 
+               functor_manager_operation_type op)
+        {
+          switch (op) {
+          case clone_functor_tag: 
+            out_buffer.obj_ref.obj_ptr = in_buffer.obj_ref.obj_ptr;
+            return;
+
+          case move_functor_tag:
+            out_buffer.obj_ref.obj_ptr = in_buffer.obj_ref.obj_ptr;
+            in_buffer.obj_ref.obj_ptr = 0;
+            return;
+
+          case destroy_functor_tag:
+            out_buffer.obj_ref.obj_ptr = 0;
+            return;
+
+          case check_functor_type_tag:
+            {
+              const BOOST_FUNCTION_STD_NS::type_info& check_type 
+                = *out_buffer.type.type;
+
+              // Check whether we have the same type. We can add
+              // cv-qualifiers, but we can't take them away.
+              if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(F))
+                  && (!in_buffer.obj_ref.is_const_qualified 
+                      || out_buffer.type.const_qualified)
+                  && (!in_buffer.obj_ref.is_volatile_qualified
+                      || out_buffer.type.volatile_qualified))
+                out_buffer.obj_ptr = in_buffer.obj_ref.obj_ptr;
+              else
+                out_buffer.obj_ptr = 0;
+            }
+            return;
+
+          case get_functor_type_tag:
+            out_buffer.type.type = &typeid(F);
+            out_buffer.type.const_qualified = in_buffer.obj_ref.is_const_qualified;
+            out_buffer.type.volatile_qualified = in_buffer.obj_ref.is_volatile_qualified;
+            return;
+          }
+        }
+      };
+
+      /**
+       * Determine if boost::function can use the small-object
+       * optimization with the function object type F.
+       */
+      template<typename F>
+      struct function_allows_small_object_optimization
+      {
+        BOOST_STATIC_CONSTANT
+          (bool, 
+           value = ((sizeof(F) <= sizeof(function_buffer) &&
+                     (alignment_of<function_buffer>::value 
+                      % alignment_of<F>::value == 0))));
+      };
+
+      template <typename F,typename A>
+      struct functor_wrapper: public F, public A
+      {
+        functor_wrapper( F f, A a ):
+          F(f),
+          A(a)
+        {
+        }
+      };
+
+      /**
+       * The functor_manager class contains a static function "manage" which
+       * can clone or destroy the given function/function object pointer.
+       */
+      template<typename Functor>
+      struct functor_manager_common
+      {
+        typedef Functor functor_type;
+
+        // Function pointers
+        static inline void
+        manage_ptr(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op)
+        {
+          if (op == clone_functor_tag)
+            out_buffer.func_ptr = in_buffer.func_ptr;
+          else if (op == move_functor_tag) {
+            out_buffer.func_ptr = in_buffer.func_ptr;
+            in_buffer.func_ptr = 0;
+          } else if (op == destroy_functor_tag)
+            out_buffer.func_ptr = 0;
+          else if (op == check_functor_type_tag) {
+            const BOOST_FUNCTION_STD_NS::type_info& check_type 
+              = *out_buffer.type.type;
+            if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
+              out_buffer.obj_ptr = &in_buffer.func_ptr;
+            else
+              out_buffer.obj_ptr = 0;
+          } else /* op == get_functor_type_tag */ {
+            out_buffer.type.type = &typeid(Functor);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;
+          }
+        }
+
+        // Function objects that fit in the small-object buffer.
+        static inline void
+        manage_small(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op)
+        {
+          if (op == clone_functor_tag || op == move_functor_tag) {
+            const functor_type* in_functor = 
+              reinterpret_cast<const functor_type*>(&in_buffer.data);
+            new ((void*)&out_buffer.data) functor_type(*in_functor);
+
+            if (op == move_functor_tag) {
+              reinterpret_cast<functor_type*>(&in_buffer.data)->~Functor();
+            }
+          } else if (op == destroy_functor_tag) {
+            // Some compilers (Borland, vc6, ...) are unhappy with ~functor_type.
+            reinterpret_cast<functor_type*>(&out_buffer.data)->~Functor();
+          } else if (op == check_functor_type_tag) {
+            const BOOST_FUNCTION_STD_NS::type_info& check_type 
+              = *out_buffer.type.type;
+            if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
+              out_buffer.obj_ptr = &in_buffer.data;
+            else
+              out_buffer.obj_ptr = 0;
+          } else /* op == get_functor_type_tag */ {
+            out_buffer.type.type = &typeid(Functor);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;            
+          }
+        }
+      };
+
+      template<typename Functor>
+      struct functor_manager
+      {
+      private:
+        typedef Functor functor_type;
+
+        // Function pointers
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, function_ptr_tag)
+        {
+          functor_manager_common<Functor>::manage_ptr(in_buffer,out_buffer,op);
+        }
+
+        // Function objects that fit in the small-object buffer.
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, mpl::true_)
+        {
+          functor_manager_common<Functor>::manage_small(in_buffer,out_buffer,op);
+        }
+        
+        // Function objects that require heap allocation
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, mpl::false_)
+        {
+          if (op == clone_functor_tag) {
+            // Clone the functor
+            // GCC 2.95.3 gets the CV qualifiers wrong here, so we
+            // can't do the static_cast that we should do.
+            const functor_type* f =
+              (const functor_type*)(in_buffer.obj_ptr);
+            functor_type* new_f = new functor_type(*f);
+            out_buffer.obj_ptr = new_f;
+          } else if (op == move_functor_tag) {
+            out_buffer.obj_ptr = in_buffer.obj_ptr;
+            in_buffer.obj_ptr = 0;
+          } else if (op == destroy_functor_tag) {
+            /* Cast from the void pointer to the functor pointer type */
+            functor_type* f =
+              static_cast<functor_type*>(out_buffer.obj_ptr);
+            delete f;
+            out_buffer.obj_ptr = 0;
+          } else if (op == check_functor_type_tag) {
+            const BOOST_FUNCTION_STD_NS::type_info& check_type
+              = *out_buffer.type.type;
+            if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
+              out_buffer.obj_ptr = in_buffer.obj_ptr;
+            else
+              out_buffer.obj_ptr = 0;
+          } else /* op == get_functor_type_tag */ {
+            out_buffer.type.type = &typeid(Functor);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;
+          }
+        }
+
+        // For function objects, we determine whether the function
+        // object can use the small-object optimization buffer or
+        // whether we need to allocate it on the heap.
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, function_obj_tag)
+        {
+          manager(in_buffer, out_buffer, op,
+                  mpl::bool_<(function_allows_small_object_optimization<functor_type>::value)>());
+        }
+
+        // For member pointers, we use the small-object optimization buffer.
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, member_ptr_tag)
+        {
+          manager(in_buffer, out_buffer, op, mpl::true_());
+        }
+
+      public:
+        /* Dispatch to an appropriate manager based on whether we have a
+           function pointer or a function object pointer. */
+        static inline void
+        manage(const function_buffer& in_buffer, function_buffer& out_buffer, 
+               functor_manager_operation_type op)
+        {
+          typedef typename get_function_tag<functor_type>::type tag_type;
+          switch (op) {
+          case get_functor_type_tag:
+            out_buffer.type.type = &typeid(functor_type);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;
+            return;
+
+          default:
+            manager(in_buffer, out_buffer, op, tag_type());
+            return;
+          }
+        }
+      };
+
+      template<typename Functor, typename Allocator>
+      struct functor_manager_a
+      {
+      private:
+        typedef Functor functor_type;
+
+        // Function pointers
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, function_ptr_tag)
+        {
+          functor_manager_common<Functor>::manage_ptr(in_buffer,out_buffer,op);
+        }
+
+        // Function objects that fit in the small-object buffer.
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, mpl::true_)
+        {
+          functor_manager_common<Functor>::manage_small(in_buffer,out_buffer,op);
+        }
+        
+        // Function objects that require heap allocation
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, mpl::false_)
+        {
+          typedef functor_wrapper<Functor,Allocator> functor_wrapper_type;
+          typedef typename Allocator::template rebind<functor_wrapper_type>::other
+            wrapper_allocator_type;
+          typedef typename wrapper_allocator_type::pointer wrapper_allocator_pointer_type;
+
+          if (op == clone_functor_tag) {
+            // Clone the functor
+            // GCC 2.95.3 gets the CV qualifiers wrong here, so we
+            // can't do the static_cast that we should do.
+            const functor_wrapper_type* f =
+              (const functor_wrapper_type*)(in_buffer.obj_ptr);
+            wrapper_allocator_type wrapper_allocator(static_cast<Allocator const &>(*f));
+            wrapper_allocator_pointer_type copy = wrapper_allocator.allocate(1);
+            wrapper_allocator.construct(copy, *f);
+
+            // Get back to the original pointer type
+            functor_wrapper_type* new_f = static_cast<functor_wrapper_type*>(copy);
+            out_buffer.obj_ptr = new_f;
+          } else if (op == move_functor_tag) {
+            out_buffer.obj_ptr = in_buffer.obj_ptr;
+            in_buffer.obj_ptr = 0;
+          } else if (op == destroy_functor_tag) {
+            /* Cast from the void pointer to the functor_wrapper_type */
+            functor_wrapper_type* victim =
+              static_cast<functor_wrapper_type*>(in_buffer.obj_ptr);
+            wrapper_allocator_type wrapper_allocator(static_cast<Allocator const &>(*victim));
+            wrapper_allocator.destroy(victim);
+            wrapper_allocator.deallocate(victim,1);
+            out_buffer.obj_ptr = 0;
+          } else if (op == check_functor_type_tag) {
+            const BOOST_FUNCTION_STD_NS::type_info& check_type 
+              = *out_buffer.type.type;
+            if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
+              out_buffer.obj_ptr = in_buffer.obj_ptr;
+            else
+              out_buffer.obj_ptr = 0;
+          } else /* op == get_functor_type_tag */ {
+            out_buffer.type.type = &typeid(Functor);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;
+          }
+        }
+
+        // For function objects, we determine whether the function
+        // object can use the small-object optimization buffer or
+        // whether we need to allocate it on the heap.
+        static inline void
+        manager(const function_buffer& in_buffer, function_buffer& out_buffer, 
+                functor_manager_operation_type op, function_obj_tag)
+        {
+          manager(in_buffer, out_buffer, op,
+                  mpl::bool_<(function_allows_small_object_optimization<functor_type>::value)>());
+        }
+
+      public:
+        /* Dispatch to an appropriate manager based on whether we have a
+           function pointer or a function object pointer. */
+        static inline void
+        manage(const function_buffer& in_buffer, function_buffer& out_buffer, 
+               functor_manager_operation_type op)
+        {
+          typedef typename get_function_tag<functor_type>::type tag_type;
+          switch (op) {
+          case get_functor_type_tag:
+            out_buffer.type.type = &typeid(functor_type);
+            out_buffer.type.const_qualified = false;
+            out_buffer.type.volatile_qualified = false;
+            return;
+
+          default:
+            manager(in_buffer, out_buffer, op, tag_type());
+            return;
+          }
+        }
+      };
+
+      // A type that is only used for comparisons against zero
+      struct useless_clear_type {};
+
+#ifdef BOOST_NO_SFINAE
+      // These routines perform comparisons between a Boost.Function
+      // object and an arbitrary function object (when the last
+      // parameter is mpl::bool_<false>) or against zero (when the
+      // last parameter is mpl::bool_<true>). They are only necessary
+      // for compilers that don't support SFINAE.
+      template<typename Function, typename Functor>
+        bool
+        compare_equal(const Function& f, const Functor&, int, mpl::bool_<true>)
+        { return f.empty(); }
+
+      template<typename Function, typename Functor>
+        bool
+        compare_not_equal(const Function& f, const Functor&, int,
+                          mpl::bool_<true>)
+        { return !f.empty(); }
+
+      template<typename Function, typename Functor>
+        bool
+        compare_equal(const Function& f, const Functor& g, long,
+                      mpl::bool_<false>)
+        {
+          if (const Functor* fp = f.template target<Functor>())
+            return function_equal(*fp, g);
+          else return false;
+        }
+
+      template<typename Function, typename Functor>
+        bool
+        compare_equal(const Function& f, const reference_wrapper<Functor>& g,
+                      int, mpl::bool_<false>)
+        {
+          if (const Functor* fp = f.template target<Functor>())
+            return fp == g.get_pointer();
+          else return false;
+        }
+
+      template<typename Function, typename Functor>
+        bool
+        compare_not_equal(const Function& f, const Functor& g, long,
+                          mpl::bool_<false>)
+        {
+          if (const Functor* fp = f.template target<Functor>())
+            return !function_equal(*fp, g);
+          else return true;
+        }
+
+      template<typename Function, typename Functor>
+        bool
+        compare_not_equal(const Function& f,
+                          const reference_wrapper<Functor>& g, int,
+                          mpl::bool_<false>)
+        {
+          if (const Functor* fp = f.template target<Functor>())
+            return fp != g.get_pointer();
+          else return true;
+        }
+#endif // BOOST_NO_SFINAE
+
+      /**
+       * Stores the "manager" portion of the vtable for a
+       * boost::function object.
+       */
+      struct vtable_base
+      {
+        void (*manager)(const function_buffer& in_buffer, 
+                        function_buffer& out_buffer, 
+                        functor_manager_operation_type op);
+      };
+    } // end namespace function
+  } // end namespace detail
+
+/**
+ * The function_base class contains the basic elements needed for the
+ * function1, function2, function3, etc. classes. It is common to all
+ * functions (and as such can be used to tell if we have one of the
+ * functionN objects).
+ */
+class function_base
+{
+public:
+  function_base() : vtable(0) { }
+
+  /** Determine if the function is empty (i.e., has no target). */
+  bool empty() const { return !vtable; }
+
+  /** Retrieve the type of the stored function object, or typeid(void)
+      if this is empty. */
+  const BOOST_FUNCTION_STD_NS::type_info& target_type() const
+  {
+    if (!vtable) return typeid(void);
+
+    detail::function::function_buffer type;
+    vtable->manager(functor, type, detail::function::get_functor_type_tag);
+    return *type.type.type;
+  }
+
+  template<typename Functor>
+    Functor* target()
+    {
+      if (!vtable) return 0;
+
+      detail::function::function_buffer type_result;
+      type_result.type.type = &typeid(Functor);
+      type_result.type.const_qualified = is_const<Functor>::value;
+      type_result.type.volatile_qualified = is_volatile<Functor>::value;
+      vtable->manager(functor, type_result, 
+                      detail::function::check_functor_type_tag);
+      return static_cast<Functor*>(type_result.obj_ptr);
+    }
+
+  template<typename Functor>
+#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    const Functor* target( Functor * = 0 ) const
+#else
+    const Functor* target() const
+#endif
+    {
+      if (!vtable) return 0;
+
+      detail::function::function_buffer type_result;
+      type_result.type.type = &typeid(Functor);
+      type_result.type.const_qualified = true;
+      type_result.type.volatile_qualified = is_volatile<Functor>::value;
+      vtable->manager(functor, type_result, 
+                      detail::function::check_functor_type_tag);
+      // GCC 2.95.3 gets the CV qualifiers wrong here, so we
+      // can't do the static_cast that we should do.
+      return (const Functor*)(type_result.obj_ptr);
+    }
+
+  template<typename F>
+    bool contains(const F& f) const
+    {
+#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+      if (const F* fp = this->target( (F*)0 ))
+#else
+      if (const F* fp = this->template target<F>())
+#endif
+      {
+        return function_equal(*fp, f);
+      } else {
+        return false;
+      }
+    }
+
+#if defined(__GNUC__) && __GNUC__ == 3 && __GNUC_MINOR__ <= 3
+  // GCC 3.3 and newer cannot copy with the global operator==, due to
+  // problems with instantiation of function return types before it
+  // has been verified that the argument types match up.
+  template<typename Functor>
+    BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+    operator==(Functor g) const
+    {
+      if (const Functor* fp = target<Functor>())
+        return function_equal(*fp, g);
+      else return false;
+    }
+
+  template<typename Functor>
+    BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+    operator!=(Functor g) const
+    {
+      if (const Functor* fp = target<Functor>())
+        return !function_equal(*fp, g);
+      else return true;
+    }
+#endif
+
+public: // should be protected, but GCC 2.95.3 will fail to allow access
+  detail::function::vtable_base* vtable;
+  mutable detail::function::function_buffer functor;
+};
+
+/**
+ * The bad_function_call exception class is thrown when a boost::function
+ * object is invoked
+ */
+class bad_function_call : public std::runtime_error
+{
+public:
+  bad_function_call() : std::runtime_error("call to empty boost::function") {}
+};
+
+#ifndef BOOST_NO_SFINAE
+inline bool operator==(const function_base& f,
+                       detail::function::useless_clear_type*)
+{
+  return f.empty();
+}
+
+inline bool operator!=(const function_base& f,
+                       detail::function::useless_clear_type*)
+{
+  return !f.empty();
+}
+
+inline bool operator==(detail::function::useless_clear_type*,
+                       const function_base& f)
+{
+  return f.empty();
+}
+
+inline bool operator!=(detail::function::useless_clear_type*,
+                       const function_base& f)
+{
+  return !f.empty();
+}
+#endif
+
+#ifdef BOOST_NO_SFINAE
+// Comparisons between boost::function objects and arbitrary function objects
+template<typename Functor>
+  inline bool operator==(const function_base& f, Functor g)
+  {
+    typedef mpl::bool_<(is_integral<Functor>::value)> integral;
+    return detail::function::compare_equal(f, g, 0, integral());
+  }
+
+template<typename Functor>
+  inline bool operator==(Functor g, const function_base& f)
+  {
+    typedef mpl::bool_<(is_integral<Functor>::value)> integral;
+    return detail::function::compare_equal(f, g, 0, integral());
+  }
+
+template<typename Functor>
+  inline bool operator!=(const function_base& f, Functor g)
+  {
+    typedef mpl::bool_<(is_integral<Functor>::value)> integral;
+    return detail::function::compare_not_equal(f, g, 0, integral());
+  }
+
+template<typename Functor>
+  inline bool operator!=(Functor g, const function_base& f)
+  {
+    typedef mpl::bool_<(is_integral<Functor>::value)> integral;
+    return detail::function::compare_not_equal(f, g, 0, integral());
+  }
+#else
+
+#  if !(defined(__GNUC__) && __GNUC__ == 3 && __GNUC_MINOR__ <= 3)
+// Comparisons between boost::function objects and arbitrary function
+// objects. GCC 3.3 and before has an obnoxious bug that prevents this
+// from working.
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator==(const function_base& f, Functor g)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return function_equal(*fp, g);
+    else return false;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator==(Functor g, const function_base& f)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return function_equal(g, *fp);
+    else return false;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator!=(const function_base& f, Functor g)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return !function_equal(*fp, g);
+    else return true;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator!=(Functor g, const function_base& f)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return !function_equal(g, *fp);
+    else return true;
+  }
+#  endif
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator==(const function_base& f, reference_wrapper<Functor> g)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return fp == g.get_pointer();
+    else return false;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator==(reference_wrapper<Functor> g, const function_base& f)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return g.get_pointer() == fp;
+    else return false;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator!=(const function_base& f, reference_wrapper<Functor> g)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return fp != g.get_pointer();
+    else return true;
+  }
+
+template<typename Functor>
+  BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
+  operator!=(reference_wrapper<Functor> g, const function_base& f)
+  {
+    if (const Functor* fp = f.template target<Functor>())
+      return g.get_pointer() != fp;
+    else return true;
+  }
+
+#endif // Compiler supporting SFINAE
+
+namespace detail {
+  namespace function {
+    inline bool has_empty_target(const function_base* f)
+    {
+      return f->empty();
+    }
+
+#if BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
+    inline bool has_empty_target(const void*)
+    {
+      return false;
+    }
+#else
+    inline bool has_empty_target(...)
+    {
+      return false;
+    }
+#endif
+  } // end namespace function
+} // end namespace detail
+} // end namespace boost
+
+#undef BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL
+#undef BOOST_FUNCTION_COMPARE_TYPE_ID
+
+#endif // BOOST_FUNCTION_BASE_HEADER