diff -r 000000000000 -r e4d67989cc36 ossrv_pub/boost_apis/boost/optional/optional.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ossrv_pub/boost_apis/boost/optional/optional.hpp Tue Feb 02 02:01:42 2010 +0200 @@ -0,0 +1,922 @@ +// 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 +#include + +#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 is used when assigment of the form: +// optional 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 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 + void construct(Factory const& factory, void* address) + { + factory.BOOST_NESTED_TEMPLATE apply(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 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::value >::type aligner_; + } dummy_ ; + + public: + + void const* address() const { return &dummy_.data[0]; } + void * address() { return &dummy_.data[0]; } +} ; + +template +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 +struct types_when_is_ref +{ + typedef BOOST_DEDUCED_TYPENAME remove_reference::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 optional_base : public optional_tag +{ + private : + + typedef +#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) + BOOST_DEDUCED_TYPENAME +#endif + ::boost::detail::make_reference_content::type internal_type ; + + typedef aligned_storage storage_type ; + + typedef types_when_isnt_ref types_when_not_ref ; + typedef types_when_is_ref types_when_ref ; + + typedef optional_base 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::type is_reference_predicate ; + + typedef BOOST_DEDUCED_TYPENAME mpl::if_::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 uninitialized. + // No-throw + optional_base() + : + m_initialized(false) {} + + // Creates an optional uninitialized. + // No-throw + optional_base ( none_t ) + : + m_initialized(false) {} + + // Creates an optional initialized with 'val'. + // Can throw if T::T(T const&) does + optional_base ( argument_type val ) + : + m_initialized(false) + { + construct(val); + } + + // Creates an optional initialized with 'val' IFF cond is true, otherwise creates an uninitialzed optional. + // 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 + // 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 + 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 (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 (deep-copies the rhs value) + template + void assign ( optional const& rhs ) + { + if (is_initialized()) + { + if ( rhs.is_initialized() ) + assign_value(static_cast(rhs.get()), is_reference_predicate() ); + else destroy(); + } + else + { + if ( rhs.is_initialized() ) + construct(static_cast(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 + 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 + void construct ( Expr const& factory, in_place_factory_base const* ) + { + BOOST_STATIC_ASSERT ( ::boost::mpl::not_::value ) ; + boost_optional_detail::construct(factory, m_storage.address()); + m_initialized = true ; + } + + // Constructs in-place using the given typed factory + template + void construct ( Expr const& factory, typed_in_place_factory_base const* ) + { + BOOST_STATIC_ASSERT ( ::boost::mpl::not_::value ) ; + factory.apply(m_storage.address()) ; + m_initialized = true ; + } + + template + 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 + 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 from optional uses this function with + // 'Expr' being of type 'U' and relying on a converting constructor of T from U. + template + 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 from optional uses this function with + // 'Expr' being of type 'U' and relying on a converting assignment of T from U. + template + 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 and optional + // 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 or optional (but not optional_base<..>) + template + 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 + internal_type const* get_object() const { return static_cast(m_storage.address()); } + internal_type * get_object() { return static_cast (m_storage.address()); } + + // reference_content 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* 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 optional : public optional_detail::optional_base +{ + typedef optional_detail::optional_base base ; + + typedef BOOST_DEDUCED_TYPENAME base::unspecified_bool_type unspecified_bool_type ; + + public : + + typedef optional 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 uninitialized. + // No-throw + optional() : base() {} + + // Creates an optional uninitialized. + // No-throw + optional( none_t none_ ) : base(none_) {} + + // Creates an optional initialized with 'val'. + // Can throw if T::T(T const&) does + optional ( argument_type val ) : base(val) {} + + // Creates an optional 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 + // Requires a valid conversion from U to T. + // Can throw if T::T(U const&) does + template + explicit optional ( optional const& rhs ) + : + base() + { + if ( rhs.is_initialized() ) + this->construct(rhs.get()); + } +#endif + +#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT + // Creates an optional 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(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 and optional + // 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 + explicit optional ( Expr const& expr ) : base(expr,&expr) {} +#endif + + // Creates a deep copy of another optional + // 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 + optional& operator= ( Expr expr ) + { + this->assign_expr(expr,&expr); + return *this ; + } +#endif + + +#ifndef BOOST_OPTIONAL_NO_CONVERTING_ASSIGNMENT + // Assigns from another convertible optional (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 + optional& operator= ( optional const& rhs ) + { + this->assign(rhs); + return *this ; + } +#endif + + // Assigns from another optional (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(v) +template +inline +optional make_optional ( T const& v ) +{ + return optional(v); +} + +// Returns optional(cond,v) +template +inline +optional make_optional ( bool cond, T const& v ) +{ + return optional(cond,v); +} + +// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED. +// No-throw +template +inline +BOOST_DEDUCED_TYPENAME optional::reference_const_type +get ( optional const& opt ) +{ + return opt.get() ; +} + +template +inline +BOOST_DEDUCED_TYPENAME optional::reference_type +get ( optional& opt ) +{ + return opt.get() ; +} + +// Returns a pointer to the value if this is initialized, otherwise, returns NULL. +// No-throw +template +inline +BOOST_DEDUCED_TYPENAME optional::pointer_const_type +get ( optional const* opt ) +{ + return opt->get_ptr() ; +} + +template +inline +BOOST_DEDUCED_TYPENAME optional::pointer_type +get ( optional* opt ) +{ + return opt->get_ptr() ; +} + +// Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED. +// No-throw +template +inline +BOOST_DEDUCED_TYPENAME optional::reference_const_type +get_optional_value_or ( optional const& opt, BOOST_DEDUCED_TYPENAME optional::reference_const_type v ) +{ + return opt.get_value_or(v) ; +} + +template +inline +BOOST_DEDUCED_TYPENAME optional::reference_type +get_optional_value_or ( optional& opt, BOOST_DEDUCED_TYPENAME optional::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 +inline +BOOST_DEDUCED_TYPENAME optional::pointer_const_type +get_pointer ( optional const& opt ) +{ + return opt.get_ptr() ; +} + +template +inline +BOOST_DEDUCED_TYPENAME optional::pointer_type +get_pointer ( optional& 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 vs optional cases +// + +template +inline +bool operator == ( optional const& x, optional const& y ) +{ return equal_pointees(x,y); } + +template +inline +bool operator < ( optional const& x, optional const& y ) +{ return less_pointees(x,y); } + +template +inline +bool operator != ( optional const& x, optional const& y ) +{ return !( x == y ) ; } + +template +inline +bool operator > ( optional const& x, optional const& y ) +{ return y < x ; } + +template +inline +bool operator <= ( optional const& x, optional const& y ) +{ return !( y < x ) ; } + +template +inline +bool operator >= ( optional const& x, optional const& y ) +{ return !( x < y ) ; } + + +// +// optional vs T cases +// +template +inline +bool operator == ( optional const& x, T const& y ) +{ return equal_pointees(x, optional(y)); } + +template +inline +bool operator < ( optional const& x, T const& y ) +{ return less_pointees(x, optional(y)); } + +template +inline +bool operator != ( optional const& x, T const& y ) +{ return !( x == y ) ; } + +template +inline +bool operator > ( optional const& x, T const& y ) +{ return y < x ; } + +template +inline +bool operator <= ( optional const& x, T const& y ) +{ return !( y < x ) ; } + +template +inline +bool operator >= ( optional const& x, T const& y ) +{ return !( x < y ) ; } + +// +// T vs optional cases +// + +template +inline +bool operator == ( T const& x, optional const& y ) +{ return equal_pointees( optional(x), y ); } + +template +inline +bool operator < ( T const& x, optional const& y ) +{ return less_pointees( optional(x), y ); } + +template +inline +bool operator != ( T const& x, optional const& y ) +{ return !( x == y ) ; } + +template +inline +bool operator > ( T const& x, optional const& y ) +{ return y < x ; } + +template +inline +bool operator <= ( T const& x, optional const& y ) +{ return !( y < x ) ; } + +template +inline +bool operator >= ( T const& x, optional const& y ) +{ return !( x < y ) ; } + + +// +// optional vs none cases +// + +template +inline +bool operator == ( optional const& x, none_t ) +{ return equal_pointees(x, optional() ); } + +template +inline +bool operator < ( optional const& x, none_t ) +{ return less_pointees(x,optional() ); } + +template +inline +bool operator != ( optional const& x, none_t y ) +{ return !( x == y ) ; } + +template +inline +bool operator > ( optional const& x, none_t y ) +{ return y < x ; } + +template +inline +bool operator <= ( optional const& x, none_t y ) +{ return !( y < x ) ; } + +template +inline +bool operator >= ( optional const& x, none_t y ) +{ return !( x < y ) ; } + +// +// none vs optional cases +// + +template +inline +bool operator == ( none_t x, optional const& y ) +{ return equal_pointees(optional() ,y); } + +template +inline +bool operator < ( none_t x, optional const& y ) +{ return less_pointees(optional() ,y); } + +template +inline +bool operator != ( none_t x, optional const& y ) +{ return !( x == y ) ; } + +template +inline +bool operator > ( none_t x, optional const& y ) +{ return y < x ; } + +template +inline +bool operator <= ( none_t x, optional const& y ) +{ return !( y < x ) ; } + +template +inline +bool operator >= ( none_t x, optional 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 +inline +void optional_swap ( optional& x, optional& 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 inline void swap ( optional& x, optional& y ) +{ + optional_detail::optional_swap(x,y); +} + + +} // namespace boost + +#endif +