FCL/sftools/dev/build: comparison imgtools/imglib/boostlibrary/boost/optional/optional.hpp

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-:fa7a3cc6effd
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+// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
+//
+// 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)
+//
+// See http://www.boost.org/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  fernando_cacciola@hotmail.com
+//
+#ifndef BOOST_OPTIONAL_OPTIONAL_FLC_19NOV2002_HPP
+#define BOOST_OPTIONAL_OPTIONAL_FLC_19NOV2002_HPP
+#include<new>
+#include<algorithm>
+#include "boost/config.hpp"
+#include "boost/assert.hpp"
+#include "boost/type.hpp"
+#include "boost/type_traits/alignment_of.hpp"
+#include "boost/type_traits/type_with_alignment.hpp"
+#include "boost/type_traits/remove_reference.hpp"
+#include "boost/type_traits/is_reference.hpp"
+#include "boost/mpl/if.hpp"
+#include "boost/mpl/bool.hpp"
+#include "boost/mpl/not.hpp"
+#include "boost/detail/reference_content.hpp"
+#include "boost/none.hpp"
+#include "boost/utility/compare_pointees.hpp"
+#include "boost/optional/optional_fwd.hpp"
+#if BOOST_WORKAROUND(BOOST_MSVC, == 1200)
+// VC6.0 has the following bug:
+//   When a templated assignment operator exist, an implicit conversion
+//   constructing an optional<T> is used when assigment of the form:
+//     optional<T> opt ; opt = T(...);
+//   is compiled.
+//   However, optional's ctor is _explicit_ and the assignemt shouldn't compile.
+//   Therefore, for VC6.0 templated assignment is disabled.
+//
+#define BOOST_OPTIONAL_NO_CONVERTING_ASSIGNMENT
+#endif
+#if BOOST_WORKAROUND(BOOST_MSVC, == 1300)
+// VC7.0 has the following bug:
+//   When both a non-template and a template copy-ctor exist
+//   and the templated version is made 'explicit', the explicit is also
+//   given to the non-templated version, making the class non-implicitely-copyable.
+//
+#define BOOST_OPTIONAL_NO_CONVERTING_COPY_CTOR
+#endif
+#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) || BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION,<=700)
+// AFAICT only VC7.1 correctly resolves the overload set
+// that includes the in-place factory taking functions,
+// so for the other VC versions, in-place factory support
+// is disabled
+#define BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
+#endif
+#if BOOST_WORKAROUND(__BORLANDC__, <= 0x551)
+// BCB (5.5.1) cannot parse the nested template struct in an inplace factory.
+#define BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
+#endif
+#if !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) \
+&& BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581) )
+// BCB (up to 5.64) has the following bug:
+//   If there is a member function/operator template of the form
+//     template<class Expr> mfunc( Expr expr ) ;
+//   some calls are resolved to this even if there are other better matches.
+//   The effect of this bug is that calls to converting ctors and assignments
+//   are incrorrectly sink to this general catch-all member function template as shown above.
+#define BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
+#endif
+// Daniel Wallin discovered that bind/apply.hpp badly interacts with the apply<>
+// member template of a factory as used in the optional<> implementation.
+// He proposed this simple fix which is to move the call to apply<> outside
+// namespace boost.
+namespace boost_optional_detail
+{
+template <class T, class Factory>
+void construct(Factory const& factory, void* address)
+{
+factory.BOOST_NESTED_TEMPLATE apply<T>(address);
+}
+}
+namespace boost {
+class in_place_factory_base ;
+class typed_in_place_factory_base ;
+namespace optional_detail {
+// This local class is used instead of that in "aligned_storage.hpp"
+// because I've found the 'official' class to ICE BCB5.5
+// when some types are used with optional<>
+// (due to sizeof() passed down as a non-type template parameter)
+template <class T>
+class aligned_storage
+{
+// Borland ICEs if unnamed unions are used for this!
+union dummy_u
+{
+char data[ sizeof(T) ];
+BOOST_DEDUCED_TYPENAME type_with_alignment<
+::boost::alignment_of<T>::value >::type aligner_;
+} dummy_ ;
+public:
+void const* address() const { return &dummy_.data[0]; }
+void      * address()       { return &dummy_.data[0]; }
+} ;
+template<class T>
+struct types_when_isnt_ref
+{
+typedef T const& reference_const_type ;
+typedef T &      reference_type ;
+typedef T const* pointer_const_type ;
+typedef T *      pointer_type ;
+typedef T const& argument_type ;
+} ;
+template<class T>
+struct types_when_is_ref
+{
+typedef BOOST_DEDUCED_TYPENAME remove_reference<T>::type raw_type ;
+typedef raw_type& reference_const_type ;
+typedef raw_type& reference_type ;
+typedef raw_type* pointer_const_type ;
+typedef raw_type* pointer_type ;
+typedef raw_type& argument_type ;
+} ;
+struct optional_tag {} ;
+template<class T>
+class optional_base : public optional_tag
+{
+private :
+typedef
+#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
+BOOST_DEDUCED_TYPENAME
+#endif
+::boost::detail::make_reference_content<T>::type internal_type ;
+typedef aligned_storage<internal_type> storage_type ;
+typedef types_when_isnt_ref<T> types_when_not_ref ;
+typedef types_when_is_ref<T>   types_when_ref   ;
+typedef optional_base<T> this_type ;
+protected :
+typedef T value_type ;
+typedef mpl::true_  is_reference_tag ;
+typedef mpl::false_ is_not_reference_tag ;
+typedef BOOST_DEDUCED_TYPENAME is_reference<T>::type is_reference_predicate ;
+typedef BOOST_DEDUCED_TYPENAME mpl::if_<is_reference_predicate,types_when_ref,types_when_not_ref>::type types ;
+typedef bool (this_type::*unspecified_bool_type)() const;
+typedef BOOST_DEDUCED_TYPENAME types::reference_type       reference_type ;
+typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ;
+typedef BOOST_DEDUCED_TYPENAME types::pointer_type         pointer_type ;
+typedef BOOST_DEDUCED_TYPENAME types::pointer_const_type   pointer_const_type ;
+typedef BOOST_DEDUCED_TYPENAME types::argument_type        argument_type ;
+// Creates an optional<T> uninitialized.
+// No-throw
+optional_base()
+:
+m_initialized(false) {}
+// Creates an optional<T> uninitialized.
+// No-throw
+optional_base ( none_t )
+:
+m_initialized(false) {}
+// Creates an optional<T> initialized with 'val'.
+// Can throw if T::T(T const&) does
+optional_base ( argument_type val )
+:
+m_initialized(false)
+{
+construct(val);
+}
+// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialzed optional<T>.
+// Can throw if T::T(T const&) does
+optional_base ( bool cond, argument_type val )
+:
+m_initialized(false)
+{
+if ( cond )
+construct(val);
+}
+// Creates a deep copy of another optional<T>
+// Can throw if T::T(T const&) does
+optional_base ( optional_base const& rhs )
+:
+m_initialized(false)
+{
+if ( rhs.is_initialized() )
+construct(rhs.get_impl());
+}
+// This is used for both converting and in-place constructions.
+// Derived classes use the 'tag' to select the appropriate
+// implementation (the correct 'construct()' overload)
+template<class Expr>
+explicit optional_base ( Expr const& expr, Expr const* tag )
+:
+m_initialized(false)
+{
+construct(expr,tag);
+}
+// No-throw (assuming T::~T() doesn't)
+~optional_base() { destroy() ; }
+// Assigns from another optional<T> (deep-copies the rhs value)
+void assign ( optional_base const& rhs )
+{
+if (is_initialized())
+{
+if ( rhs.is_initialized() )
+assign_value(rhs.get_impl(), is_reference_predicate() );
+else destroy();
+}
+else
+{
+if ( rhs.is_initialized() )
+construct(rhs.get_impl());
+}
+}
+// Assigns from another _convertible_ optional<U> (deep-copies the rhs value)
+template<class U>
+void assign ( optional<U> const& rhs )
+{
+if (is_initialized())
+{
+if ( rhs.is_initialized() )
+assign_value(static_cast<value_type>(rhs.get()), is_reference_predicate() );
+else destroy();
+}
+else
+{
+if ( rhs.is_initialized() )
+construct(static_cast<value_type>(rhs.get()));
+}
+}
+// Assigns from a T (deep-copies the rhs value)
+void assign ( argument_type val )
+{
+if (is_initialized())
+assign_value(val, is_reference_predicate() );
+else construct(val);
+}
+// Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED
+// No-throw (assuming T::~T() doesn't)
+void assign ( none_t ) { destroy(); }
+#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
+template<class Expr>
+void assign_expr ( Expr const& expr, Expr const* tag )
+{
+if (is_initialized())
+assign_expr_to_initialized(expr,tag);
+else construct(expr,tag);
+}
+#endif
+public :
+// Destroys the current value, if any, leaving this UNINITIALIZED
+// No-throw (assuming T::~T() doesn't)
+void reset() { destroy(); }
+// Replaces the current value -if any- with 'val'
+void reset ( argument_type val ) { assign(val); }
+// Returns a pointer to the value if this is initialized, otherwise,
+// returns NULL.
+// No-throw
+pointer_const_type get_ptr() const { return m_initialized ? get_ptr_impl() : 0 ; }
+pointer_type       get_ptr()       { return m_initialized ? get_ptr_impl() : 0 ; }
+bool is_initialized() const { return m_initialized ; }
+protected :
+void construct ( argument_type val )
+{
+new (m_storage.address()) internal_type(val) ;
+m_initialized = true ;
+}
+#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
+// Constructs in-place using the given factory
+template<class Expr>
+void construct ( Expr const& factory, in_place_factory_base const* )
+{
+BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
+boost_optional_detail::construct<value_type>(factory, m_storage.address());
+m_initialized = true ;
+}
+// Constructs in-place using the given typed factory
+template<class Expr>
+void construct ( Expr const& factory, typed_in_place_factory_base const* )
+{
+BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
+factory.apply(m_storage.address()) ;
+m_initialized = true ;
+}
+template<class Expr>
+void assign_expr_to_initialized ( Expr const& factory, in_place_factory_base const* tag )
+{
+destroy();
+construct(factory,tag);
+}
+// Constructs in-place using the given typed factory
+template<class Expr>
+void assign_expr_to_initialized ( Expr const& factory, typed_in_place_factory_base const* tag )
+{
+destroy();
+construct(factory,tag);
+}
+#endif
+// Constructs using any expression implicitely convertible to the single argument
+// of a one-argument T constructor.
+// Converting constructions of optional<T> from optional<U> uses this function with
+// 'Expr' being of type 'U' and relying on a converting constructor of T from U.
+template<class Expr>
+void construct ( Expr const& expr, void const* )
+{
+new (m_storage.address()) internal_type(expr) ;
+m_initialized = true ;
+}
+// Assigns using a form any expression implicitely convertible to the single argument
+// of a T's assignment operator.
+// Converting assignments of optional<T> from optional<U> uses this function with
+// 'Expr' being of type 'U' and relying on a converting assignment of T from U.
+template<class Expr>
+void assign_expr_to_initialized ( Expr const& expr, void const* )
+{
+assign_value(expr, is_reference_predicate());
+}
+#ifdef BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
+// BCB5.64 (and probably lower versions) workaround.
+//   The in-place factories are supported by means of catch-all constructors
+//   and assignment operators (the functions are parameterized in terms of
+//   an arbitrary 'Expr' type)
+//   This compiler incorrectly resolves the overload set and sinks optional<T> and optional<U>
+//   to the 'Expr'-taking functions even though explicit overloads are present for them.
+//   Thus, the following overload is needed to properly handle the case when the 'lhs'
+//   is another optional.
+//
+// For VC<=70 compilers this workaround dosen't work becasue the comnpiler issues and error
+// instead of choosing the wrong overload
+//
+// Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>)
+template<class Expr>
+void construct ( Expr const& expr, optional_tag const* )
+{
+if ( expr.is_initialized() )
+{
+// An exception can be thrown here.
+// It it happens, THIS will be left uninitialized.
+new (m_storage.address()) internal_type(expr.get()) ;
+m_initialized = true ;
+}
+}
+#endif
+void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; }
+void assign_value ( argument_type val, is_reference_tag     ) { construct(val); }
+void destroy()
+{
+if ( m_initialized )
+destroy_impl(is_reference_predicate()) ;
+}
+unspecified_bool_type safe_bool() const { return m_initialized ? &this_type::is_initialized : 0 ; }
+reference_const_type get_impl() const { return dereference(get_object(), is_reference_predicate() ) ; }
+reference_type       get_impl()       { return dereference(get_object(), is_reference_predicate() ) ; }
+pointer_const_type get_ptr_impl() const { return cast_ptr(get_object(), is_reference_predicate() ) ; }
+pointer_type       get_ptr_impl()       { return cast_ptr(get_object(), is_reference_predicate() ) ; }
+private :
+// internal_type can be either T or reference_content<T>
+internal_type const* get_object() const { return static_cast<internal_type const*>(m_storage.address()); }
+internal_type *      get_object()       { return static_cast<internal_type *>     (m_storage.address()); }
+// reference_content<T> lacks an implicit conversion to T&, so the following is needed to obtain a proper reference.
+reference_const_type dereference( internal_type const* p, is_not_reference_tag ) const { return *p ; }
+reference_type       dereference( internal_type*       p, is_not_reference_tag )       { return *p ; }
+reference_const_type dereference( internal_type const* p, is_reference_tag     ) const { return p->get() ; }
+reference_type       dereference( internal_type*       p, is_reference_tag     )       { return p->get() ; }
+#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581))
+void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->internal_type::~internal_type() ; m_initialized = false ; }
+#else
+void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->T::~T() ; m_initialized = false ; }
+#endif
+void destroy_impl ( is_reference_tag     ) { m_initialized = false ; }
+// If T is of reference type, trying to get a pointer to the held value must result in a compile-time error.
+// Decent compilers should disallow conversions from reference_content<T>* to T*, but just in case,
+// the following olverloads are used to filter out the case and guarantee an error in case of T being a reference.
+pointer_const_type cast_ptr( internal_type const* p, is_not_reference_tag ) const { return p ; }
+pointer_type       cast_ptr( internal_type *      p, is_not_reference_tag )       { return p ; }
+pointer_const_type cast_ptr( internal_type const* p, is_reference_tag     ) const { return &p->get() ; }
+pointer_type       cast_ptr( internal_type *      p, is_reference_tag     )       { return &p->get() ; }
+bool m_initialized ;
+storage_type m_storage ;
+} ;
+} // namespace optional_detail
+template<class T>
+class optional : public optional_detail::optional_base<T>
+{
+typedef optional_detail::optional_base<T> base ;
+typedef BOOST_DEDUCED_TYPENAME base::unspecified_bool_type  unspecified_bool_type ;
+public :
+typedef optional<T> this_type ;
+typedef BOOST_DEDUCED_TYPENAME base::value_type           value_type ;
+typedef BOOST_DEDUCED_TYPENAME base::reference_type       reference_type ;
+typedef BOOST_DEDUCED_TYPENAME base::reference_const_type reference_const_type ;
+typedef BOOST_DEDUCED_TYPENAME base::pointer_type         pointer_type ;
+typedef BOOST_DEDUCED_TYPENAME base::pointer_const_type   pointer_const_type ;
+typedef BOOST_DEDUCED_TYPENAME base::argument_type        argument_type ;
+// Creates an optional<T> uninitialized.
+// No-throw
+optional() : base() {}
+// Creates an optional<T> uninitialized.
+// No-throw
+optional( none_t none_ ) : base(none_) {}
+// Creates an optional<T> initialized with 'val'.
+// Can throw if T::T(T const&) does
+optional ( argument_type val ) : base(val) {}
+// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional.
+// Can throw if T::T(T const&) does
+optional ( bool cond, argument_type val ) : base(cond,val) {}
+#ifndef BOOST_OPTIONAL_NO_CONVERTING_COPY_CTOR
+// NOTE: MSVC needs templated versions first
+// Creates a deep copy of another convertible optional<U>
+// Requires a valid conversion from U to T.
+// Can throw if T::T(U const&) does
+template<class U>
+explicit optional ( optional<U> const& rhs )
+:
+base()
+{
+if ( rhs.is_initialized() )
+this->construct(rhs.get());
+}
+#endif
+#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
+// Creates an optional<T> with an expression which can be either
+//  (a) An instance of InPlaceFactory (i.e. in_place(a,b,...,n);
+//  (b) An instance of TypedInPlaceFactory ( i.e. in_place<T>(a,b,...,n);
+//  (c) Any expression implicitely convertible to the single type
+//      of a one-argument T's constructor.
+//  (d*) Weak compilers (BCB) might also resolved Expr as optional<T> and optional<U>
+//       even though explicit overloads are present for these.
+// Depending on the above some T ctor is called.
+// Can throw is the resolved T ctor throws.
+template<class Expr>
+explicit optional ( Expr const& expr ) : base(expr,&expr) {}
+#endif
+// Creates a deep copy of another optional<T>
+// Can throw if T::T(T const&) does
+optional ( optional const& rhs ) : base(rhs) {}
+// No-throw (assuming T::~T() doesn't)
+~optional() {}
+#if !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION)
+// Assigns from an expression. See corresponding constructor.
+// Basic Guarantee: If the resolved T ctor throws, this is left UNINITIALIZED
+template<class Expr>
+optional& operator= ( Expr expr )
+{
+this->assign_expr(expr,&expr);
+return *this ;
+}
+#endif
+#ifndef BOOST_OPTIONAL_NO_CONVERTING_ASSIGNMENT
+// Assigns from another convertible optional<U> (converts && deep-copies the rhs value)
+// Requires a valid conversion from U to T.
+// Basic Guarantee: If T::T( U const& ) throws, this is left UNINITIALIZED
+template<class U>
+optional& operator= ( optional<U> const& rhs )
+{
+this->assign(rhs);
+return *this ;
+}
+#endif
+// Assigns from another optional<T> (deep-copies the rhs value)
+// Basic Guarantee: If T::T( T const& ) throws, this is left UNINITIALIZED
+//  (NOTE: On BCB, this operator is not actually called and left is left UNMODIFIED in case of a throw)
+optional& operator= ( optional const& rhs )
+{
+this->assign( rhs ) ;
+return *this ;
+}
+// Assigns from a T (deep-copies the rhs value)
+// Basic Guarantee: If T::( T const& ) throws, this is left UNINITIALIZED
+optional& operator= ( argument_type val )
+{
+this->assign( val ) ;
+return *this ;
+}
+// Assigns from a "none"
+// Which destroys the current value, if any, leaving this UNINITIALIZED
+// No-throw (assuming T::~T() doesn't)
+optional& operator= ( none_t none_ )
+{
+this->assign( none_ ) ;
+return *this ;
+}
+// Returns a reference to the value if this is initialized, otherwise,
+// the behaviour is UNDEFINED
+// No-throw
+reference_const_type get() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); }
+reference_type       get()       { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); }
+// Returns a copy of the value if this is initialized, 'v' otherwise
+reference_const_type get_value_or ( reference_const_type v ) const { return this->is_initialized() ? get() : v ; }
+reference_type       get_value_or ( reference_type       v )       { return this->is_initialized() ? get() : v ; }
+// Returns a pointer to the value if this is initialized, otherwise,
+// the behaviour is UNDEFINED
+// No-throw
+pointer_const_type operator->() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; }
+pointer_type       operator->()       { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; }
+// Returns a reference to the value if this is initialized, otherwise,
+// the behaviour is UNDEFINED
+// No-throw
+reference_const_type operator *() const { return this->get() ; }
+reference_type       operator *()       { return this->get() ; }
+// implicit conversion to "bool"
+// No-throw
+operator unspecified_bool_type() const { return this->safe_bool() ; }
+// This is provided for those compilers which don't like the conversion to bool
+// on some contexts.
+bool operator!() const { return !this->is_initialized() ; }
+} ;
+// Returns optional<T>(v)
+template<class T>
+inline
+optional<T> make_optional ( T const& v  )
+{
+return optional<T>(v);
+}
+// Returns optional<T>(cond,v)
+template<class T>
+inline
+optional<T> make_optional ( bool cond, T const& v )
+{
+return optional<T>(cond,v);
+}
+// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED.
+// No-throw
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type
+get ( optional<T> const& opt )
+{
+return opt.get() ;
+}
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::reference_type
+get ( optional<T>& opt )
+{
+return opt.get() ;
+}
+// Returns a pointer to the value if this is initialized, otherwise, returns NULL.
+// No-throw
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::pointer_const_type
+get ( optional<T> const* opt )
+{
+return opt->get_ptr() ;
+}
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::pointer_type
+get ( optional<T>* opt )
+{
+return opt->get_ptr() ;
+}
+// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED.
+// No-throw
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type
+get_optional_value_or ( optional<T> const& opt, BOOST_DEDUCED_TYPENAME optional<T>::reference_const_type v )
+{
+return opt.get_value_or(v) ;
+}
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::reference_type
+get_optional_value_or ( optional<T>& opt, BOOST_DEDUCED_TYPENAME optional<T>::reference_type v )
+{
+return opt.get_value_or(v) ;
+}
+// Returns a pointer to the value if this is initialized, otherwise, returns NULL.
+// No-throw
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::pointer_const_type
+get_pointer ( optional<T> const& opt )
+{
+return opt.get_ptr() ;
+}
+template<class T>
+inline
+BOOST_DEDUCED_TYPENAME optional<T>::pointer_type
+get_pointer ( optional<T>& opt )
+{
+return opt.get_ptr() ;
+}
+// optional's relational operators ( ==, !=, <, >, <=, >= ) have deep-semantics (compare values).
+// WARNING: This is UNLIKE pointers. Use equal_pointees()/less_pointess() in generic code instead.
+//
+// optional<T> vs optional<T> cases
+//
+template<class T>
+inline
+bool operator == ( optional<T> const& x, optional<T> const& y )
+{ return equal_pointees(x,y); }
+template<class T>
+inline
+bool operator < ( optional<T> const& x, optional<T> const& y )
+{ return less_pointees(x,y); }
+template<class T>
+inline
+bool operator != ( optional<T> const& x, optional<T> const& y )
+{ return !( x == y ) ; }
+template<class T>
+inline
+bool operator > ( optional<T> const& x, optional<T> const& y )
+{ return y < x ; }
+template<class T>
+inline
+bool operator <= ( optional<T> const& x, optional<T> const& y )
+{ return !( y < x ) ; }
+template<class T>
+inline
+bool operator >= ( optional<T> const& x, optional<T> const& y )
+{ return !( x < y ) ; }
+//
+// optional<T> vs T cases
+//
+template<class T>
+inline
+bool operator == ( optional<T> const& x, T const& y )
+{ return equal_pointees(x, optional<T>(y)); }
+template<class T>
+inline
+bool operator < ( optional<T> const& x, T const& y )
+{ return less_pointees(x, optional<T>(y)); }
+template<class T>
+inline
+bool operator != ( optional<T> const& x, T const& y )
+{ return !( x == y ) ; }
+template<class T>
+inline
+bool operator > ( optional<T> const& x, T const& y )
+{ return y < x ; }
+template<class T>
+inline
+bool operator <= ( optional<T> const& x, T const& y )
+{ return !( y < x ) ; }
+template<class T>
+inline
+bool operator >= ( optional<T> const& x, T const& y )
+{ return !( x < y ) ; }
+//
+// T vs optional<T> cases
+//
+template<class T>
+inline
+bool operator == ( T const& x, optional<T> const& y )
+{ return equal_pointees( optional<T>(x), y ); }
+template<class T>
+inline
+bool operator < ( T const& x, optional<T> const& y )
+{ return less_pointees( optional<T>(x), y ); }
+template<class T>
+inline
+bool operator != ( T const& x, optional<T> const& y )
+{ return !( x == y ) ; }
+template<class T>
+inline
+bool operator > ( T const& x, optional<T> const& y )
+{ return y < x ; }
+template<class T>
+inline
+bool operator <= ( T const& x, optional<T> const& y )
+{ return !( y < x ) ; }
+template<class T>
+inline
+bool operator >= ( T const& x, optional<T> const& y )
+{ return !( x < y ) ; }
+//
+// optional<T> vs none cases
+//
+template<class T>
+inline
+bool operator == ( optional<T> const& x, none_t )
+{ return equal_pointees(x, optional<T>() ); }
+template<class T>
+inline
+bool operator < ( optional<T> const& x, none_t )
+{ return less_pointees(x,optional<T>() ); }
+template<class T>
+inline
+bool operator != ( optional<T> const& x, none_t y )
+{ return !( x == y ) ; }
+template<class T>
+inline
+bool operator > ( optional<T> const& x, none_t y )
+{ return y < x ; }
+template<class T>
+inline
+bool operator <= ( optional<T> const& x, none_t y )
+{ return !( y < x ) ; }
+template<class T>
+inline
+bool operator >= ( optional<T> const& x, none_t y )
+{ return !( x < y ) ; }
+//
+// none vs optional<T> cases
+//
+template<class T>
+inline
+bool operator == ( none_t x, optional<T> const& y )
+{ return equal_pointees(optional<T>() ,y); }
+template<class T>
+inline
+bool operator < ( none_t x, optional<T> const& y )
+{ return less_pointees(optional<T>() ,y); }
+template<class T>
+inline
+bool operator != ( none_t x, optional<T> const& y )
+{ return !( x == y ) ; }
+template<class T>
+inline
+bool operator > ( none_t x, optional<T> const& y )
+{ return y < x ; }
+template<class T>
+inline
+bool operator <= ( none_t x, optional<T> const& y )
+{ return !( y < x ) ; }
+template<class T>
+inline
+bool operator >= ( none_t x, optional<T> const& y )
+{ return !( x < y ) ; }
+//
+// The following swap implementation follows the GCC workaround as found in
+//  "boost/detail/compressed_pair.hpp"
+//
+namespace optional_detail {
+// GCC < 3.2 gets the using declaration at namespace scope (FLC, DWA)
+#if BOOST_WORKAROUND(__GNUC__, < 3)                             \
+|| BOOST_WORKAROUND(__GNUC__, == 3) && __GNUC_MINOR__ <= 2
+using std::swap;
+#define BOOST_OPTIONAL_STD_SWAP_INTRODUCED_AT_NS_SCOPE
+#endif
+// optional's swap:
+// If both are initialized, calls swap(T&, T&). If this swap throws, both will remain initialized but their values are now unspecified.
+// If only one is initialized, calls U.reset(*I), THEN I.reset().
+// If U.reset(*I) throws, both are left UNCHANGED (U is kept uinitialized and I is never reset)
+// If both are uninitialized, do nothing (no-throw)
+template<class T>
+inline
+void optional_swap ( optional<T>& x, optional<T>& y )
+{
+if ( !x && !!y )
+{
+x.reset(*y);
+y.reset();
+}
+else if ( !!x && !y )
+{
+y.reset(*x);
+x.reset();
+}
+else if ( !!x && !!y )
+{
+// GCC > 3.2 and all other compilers have the using declaration at function scope (FLC)
+#ifndef BOOST_OPTIONAL_STD_SWAP_INTRODUCED_AT_NS_SCOPE
+// allow for Koenig lookup
+using std::swap ;
+#endif
+swap(*x,*y);
+}
+}
+} // namespace optional_detail
+template<class T> inline void swap ( optional<T>& x, optional<T>& y )
+{
+optional_detail::optional_swap(x,y);
+}
+} // namespace boost
+#endif