// 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.
+// See http://www.boost.org/libs/optional for documentation.
//
// You are welcome to contact the author at:
// fernando_cacciola@hotmail.com
#ifndef BOOST_OPTIONAL_FLC_19NOV2002_HPP
#define BOOST_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/detail/none_t.hpp"
-#include "boost/utility/compare_pointees.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__, <= 0x564)
-// 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
-
-
-namespace boost {
-
-class InPlaceFactoryBase ;
-class TypedInPlaceFactoryBase ;
-
-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 BOOST_DEDUCED_TYPENAME 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 ( detail::none_t const& )
- :
- 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 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)
- // Basic Guarantee: If T::T( T const& ) throws, this is left UNINITIALIZED
- void assign ( optional_base const& rhs )
- {
- destroy();
- if ( rhs.is_initialized() )
- construct(rhs.get_impl());
- }
-
- // Assigns from a T (deep-copies the rhs value)
- // Basic Guarantee: If T::( T const& ) throws, this is left UNINITIALIZED
- void assign ( argument_type val )
- {
- destroy();
- construct(val);
- }
-
- // Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED
- // No-throw (assuming T::~T() doesn't)
- void assign ( detail::none_t const& ) { destroy(); }
-
-#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
- template<class Expr>
- void assign_expr ( Expr const& expr, Expr const* tag )
- {
- destroy();
- 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'
- // Basic Guarantee: If T::T( T const& ) throws this is left UNINITIALIZED.
- 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, InPlaceFactoryBase const* )
- {
- BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
- factory.BOOST_NESTED_TEMPLATE apply<value_type>(m_storage.address()) ;
- m_initialized = true ;
- }
-
- // Constructs in-place using the given typed factory
- template<class Expr>
- void construct ( Expr const& factory, TypedInPlaceFactoryBase const* )
- {
- BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
- factory.apply(m_storage.address()) ;
- m_initialized = true ;
- }
-#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 ;
- }
-
-#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 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() ; }
-
- void destroy_impl ( is_not_reference_tag ) { get_impl().~T() ; m_initialized = false ; }
- 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 ; }
-
- 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( detail::none_t const& none_ ) : base(none_) {}
-
- // Creates an optional<T> initialized with 'val'.
- // Can throw if T::T(T const&) does
- optional ( argument_type val ) : base(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->destroy(); // no-throw
-
- if ( rhs.is_initialized() )
- {
- // An exception can be thrown here.
- // It it happens, THIS will be left uninitialized.
- this->assign(rhs.get());
- }
- 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= ( detail::none_t const& 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 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 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 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.
-
-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 ) ; }
-
-template<class T>
-inline
-bool operator == ( optional<T> const& x, detail::none_t const& )
-{ return equal_pointees(x, optional<T>() ); }
-
-template<class T>
-inline
-bool operator < ( optional<T> const& x, detail::none_t const& )
-{ return less_pointees(x,optional<T>() ); }
-
-template<class T>
-inline
-bool operator != ( optional<T> const& x, detail::none_t const& y )
-{ return !( x == y ) ; }
-
-template<class T>
-inline
-bool operator > ( optional<T> const& x, detail::none_t const& y )
-{ return y < x ; }
-
-template<class T>
-inline
-bool operator <= ( optional<T> const& x, detail::none_t const& y )
-{ return !( y < x ) ; }
-
-template<class T>
-inline
-bool operator >= ( optional<T> const& x, detail::none_t const& y )
-{ return !( x < y ) ; }
-
-template<class T>
-inline
-bool operator == ( detail::none_t const& x, optional<T> const& y )
-{ return equal_pointees(optional<T>() ,y); }
-
-template<class T>
-inline
-bool operator < ( detail::none_t const& x, optional<T> const& y )
-{ return less_pointees(optional<T>() ,y); }
-
-template<class T>
-inline
-bool operator != ( detail::none_t const& x, optional<T> const& y )
-{ return !( x == y ) ; }
-
-template<class T>
-inline
-bool operator > ( detail::none_t const& x, optional<T> const& y )
-{ return y < x ; }
-
-template<class T>
-inline
-bool operator <= ( detail::none_t const& x, optional<T> const& y )
-{ return !( y < x ) ; }
-
-template<class T>
-inline
-bool operator >= ( detail::none_t const& 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&), with whatever exception guarantess are given there.
-// If only one is initialized, calls I.reset() and U.reset(*I), with the Basic Guarantee
-// 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); // Basic guarantee.
- y.reset();
- }
- else if ( !!x && !y )
- {
- y.reset(*x); // Basic guarantee.
- 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
+#include "boost/optional/optional.hpp"
#endif