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Diffstat (limited to 'boost/optional/detail/old_optional_implementation.hpp')
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diff --git a/boost/optional/detail/old_optional_implementation.hpp b/boost/optional/detail/old_optional_implementation.hpp new file mode 100644 index 0000000000..f2e6718402 --- /dev/null +++ b/boost/optional/detail/old_optional_implementation.hpp @@ -0,0 +1,1059 @@ +// Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal. +// Copyright (C) 2014-2016 Andrzej Krzemienski. +// +// 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/libs/optional for documentation. +// +// You are welcome to contact the maintainer at: +// akrzemi1@gmail.com + +#ifndef BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP +#define BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP + +#include <boost/detail/reference_content.hpp> +#include <boost/mpl/bool.hpp> +#include <boost/mpl/if.hpp> +#include <boost/mpl/not.hpp> +#include <boost/type_traits/is_reference.hpp> + +namespace boost { + +namespace optional_detail { + + +template<class T> +struct types_when_isnt_ref +{ + typedef T const& reference_const_type ; + typedef T & reference_type ; +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + typedef T && rval_reference_type ; + typedef T && reference_type_of_temporary_wrapper; +#ifdef BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES + // GCC 4.4 has support for an early draft of rvalue references. The conforming version below + // causes warnings about returning references to a temporary. + static T&& move(T&& r) { return r; } +#else + static rval_reference_type move(reference_type r) { return boost::move(r); } +#endif +#endif + 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 ; +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + typedef BOOST_DEDUCED_TYPENAME remove_const<raw_type>::type&& rval_reference_type ; + typedef raw_type& reference_type_of_temporary_wrapper; + static reference_type move(reference_type r) { return r; } +#endif + typedef raw_type* pointer_const_type ; + typedef raw_type* pointer_type ; + typedef raw_type& argument_type ; +} ; + +template <class To, class From> +void prevent_binding_rvalue_ref_to_optional_lvalue_ref() +{ +#ifndef BOOST_OPTIONAL_CONFIG_ALLOW_BINDING_TO_RVALUES + BOOST_STATIC_ASSERT_MSG( + !boost::is_lvalue_reference<To>::value || !boost::is_rvalue_reference<From>::value, + "binding rvalue references to optional lvalue references is disallowed"); +#endif +} + +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 ; + + public: + typedef BOOST_DEDUCED_TYPENAME mpl::if_<is_reference_predicate,types_when_ref,types_when_not_ref>::type types ; + + protected: + typedef BOOST_DEDUCED_TYPENAME types::reference_type reference_type ; + typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ; +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + typedef BOOST_DEDUCED_TYPENAME types::rval_reference_type rval_reference_type ; + typedef BOOST_DEDUCED_TYPENAME types::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ; +#endif + 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); + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // move-construct an optional<T> initialized from an rvalue-ref to 'val'. + // Can throw if T::T(T&&) does + optional_base ( rval_reference_type val ) + : + m_initialized(false) + { + construct( boost::move(val) ); + } +#endif + + // 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()); + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Creates a deep move of another optional<T> + // Can throw if T::T(T&&) does + optional_base ( optional_base&& rhs ) + : + m_initialized(false) + { + if ( rhs.is_initialized() ) + construct( boost::move(rhs.get_impl()) ); + } +#endif + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + + template<class Expr, class PtrExpr> + explicit optional_base ( Expr&& expr, PtrExpr const* tag ) + : + m_initialized(false) + { + construct(boost::forward<Expr>(expr),tag); + } + +#else + // 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); + } + +#endif + + + // 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()); + } + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Assigns from another optional<T> (deep-moves the rhs value) + void assign ( optional_base&& rhs ) + { + if (is_initialized()) + { + if ( rhs.is_initialized() ) + assign_value(boost::move(rhs.get_impl()), is_reference_predicate() ); + else destroy(); + } + else + { + if ( rhs.is_initialized() ) + construct(boost::move(rhs.get_impl())); + } + } +#endif + + // 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() ) +#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES + assign_value(rhs.get(), is_reference_predicate() ); +#else + assign_value(static_cast<value_type>(rhs.get()), is_reference_predicate() ); +#endif + + else destroy(); + } + else + { + if ( rhs.is_initialized() ) +#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES + construct(rhs.get()); +#else + construct(static_cast<value_type>(rhs.get())); +#endif + } + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // move-assigns from another _convertible_ optional<U> (deep-moves from the rhs value) + template<class U> + void assign ( optional<U>&& rhs ) + { + typedef BOOST_DEDUCED_TYPENAME optional<U>::rval_reference_type ref_type; + if (is_initialized()) + { + if ( rhs.is_initialized() ) + assign_value(static_cast<ref_type>(rhs.get()), is_reference_predicate() ); + else destroy(); + } + else + { + if ( rhs.is_initialized() ) + construct(static_cast<ref_type>(rhs.get())); + } + } +#endif + + // 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); + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Assigns from a T (deep-moves the rhs value) + void assign ( rval_reference_type val ) + { + if (is_initialized()) + assign_value( boost::move(val), is_reference_predicate() ); + else construct( boost::move(val) ); + } +#endif + + // Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED + // No-throw (assuming T::~T() doesn't) + void assign ( none_t ) BOOST_NOEXCEPT { destroy(); } + +#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + template<class Expr, class ExprPtr> + void assign_expr ( Expr&& expr, ExprPtr const* tag ) + { + if (is_initialized()) + assign_expr_to_initialized(boost::forward<Expr>(expr),tag); + else construct(boost::forward<Expr>(expr),tag); + } +#else + 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 + +#endif + + public : + + // **DEPPRECATED** Destroys the current value, if any, leaving this UNINITIALIZED + // No-throw (assuming T::~T() doesn't) + void reset() BOOST_NOEXCEPT { destroy(); } + + // **DEPPRECATED** 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_DETAIL_NO_RVALUE_REFERENCES + void construct ( rval_reference_type val ) + { + ::new (m_storage.address()) internal_type( types::move(val) ) ; + m_initialized = true ; + } +#endif + + +#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES) + // Constructs in-place + // upon exception *this is always uninitialized + template<class... Args> + void emplace_assign ( Args&&... args ) + { + destroy(); + ::new (m_storage.address()) internal_type( boost::forward<Args>(args)... ); + m_initialized = true ; + } +#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) + template<class Arg> + void emplace_assign ( Arg&& arg ) + { + destroy(); + ::new (m_storage.address()) internal_type( boost::forward<Arg>(arg) ); + m_initialized = true ; + } + + void emplace_assign () + { + destroy(); + ::new (m_storage.address()) internal_type(); + m_initialized = true ; + } +#else + template<class Arg> + void emplace_assign ( const Arg& arg ) + { + destroy(); + ::new (m_storage.address()) internal_type( arg ); + m_initialized = true ; + } + + template<class Arg> + void emplace_assign ( Arg& arg ) + { + destroy(); + ::new (m_storage.address()) internal_type( arg ); + m_initialized = true ; + } + + void emplace_assign () + { + destroy(); + ::new (m_storage.address()) internal_type(); + m_initialized = true ; + } +#endif + +#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Constructs in-place using the given factory + template<class Expr> + void construct ( Expr&& 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&& 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&& 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&& factory, typed_in_place_factory_base const* tag ) + { + destroy(); + construct(factory,tag); + } + +#else + // 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 + +#endif + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Constructs using any expression implicitly 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&& expr, void const* ) + { + new (m_storage.address()) internal_type(boost::forward<Expr>(expr)) ; + m_initialized = true ; + } + + // Assigns using a form any expression implicitly 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&& expr, void const* ) + { + assign_value(boost::forward<Expr>(expr), is_reference_predicate()); + } +#else + // Constructs using any expression implicitly 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 implicitly 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()); + } + +#endif + +#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 + // +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>) + template<class Expr> + void construct ( Expr&& 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(types::move(expr.get())) ; + m_initialized = true ; + } + } +#else + // 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 +#endif // defined BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION + + void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; } + void assign_value ( argument_type val, is_reference_tag ) { construct(val); } +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + void assign_value ( rval_reference_type val, is_not_reference_tag ) { get_impl() = static_cast<rval_reference_type>(val); } + void assign_value ( rval_reference_type val, is_reference_tag ) { construct( static_cast<rval_reference_type>(val) ); } +#endif + + void destroy() + { + if ( m_initialized ) + destroy_impl(is_reference_predicate()) ; + } + + 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> +#if defined(BOOST_OPTIONAL_DETAIL_USE_ATTRIBUTE_MAY_ALIAS) + // This workaround is supposed to silence GCC warnings about broken strict aliasing rules + internal_type const* get_object() const + { + union { void const* ap_pvoid; internal_type const* as_ptype; } caster = { m_storage.address() }; + return caster.as_ptype; + } + internal_type * get_object() + { + union { void* ap_pvoid; internal_type* as_ptype; } caster = { m_storage.address() }; + return caster.as_ptype; + } +#else + 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()); } +#endif + + // 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() ; 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 ; + + 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 ; +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + typedef BOOST_DEDUCED_TYPENAME base::rval_reference_type rval_reference_type ; + typedef BOOST_DEDUCED_TYPENAME base::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ; +#endif + 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() BOOST_NOEXCEPT : base() {} + + // Creates an optional<T> uninitialized. + // No-throw + optional( none_t none_ ) BOOST_NOEXCEPT : 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_DETAIL_NO_RVALUE_REFERENCES + // Creates an optional<T> initialized with 'move(val)'. + // Can throw if T::T(T &&) does + optional ( rval_reference_type val ) : base( boost::forward<T>(val) ) + {optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>();} +#endif + + // 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) {} + + // 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()); + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Creates a deep move of another convertible optional<U> + // Requires a valid conversion from U to T. + // Can throw if T::T(U&&) does + template<class U> + explicit optional ( optional<U> && rhs ) + : + base() + { + if ( rhs.is_initialized() ) + this->construct( boost::move(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 implicitly 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 if the resolved T ctor throws. +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + + + template<class Expr> + explicit optional ( Expr&& expr, + BOOST_DEDUCED_TYPENAME boost::disable_if_c< + (boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value) || + boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value >::type* = 0 + ) + : base(boost::forward<Expr>(expr),boost::addressof(expr)) + {optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>();} + +#else + template<class Expr> + explicit optional ( Expr const& expr ) : base(expr,boost::addressof(expr)) {} +#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES +#endif // !defined BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT + + // Creates a deep copy of another optional<T> + // Can throw if T::T(T const&) does + optional ( optional const& rhs ) : base( static_cast<base const&>(rhs) ) {} + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Creates a deep move of another optional<T> + // Can throw if T::T(T&&) does + optional ( optional && rhs ) + BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value) + : base( boost::move(rhs) ) + {} + +#endif + // 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 +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + + template<class Expr> + BOOST_DEDUCED_TYPENAME boost::disable_if_c< + boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value || + boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value, + optional& + >::type + operator= ( Expr&& expr ) + { + optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>(); + this->assign_expr(boost::forward<Expr>(expr),boost::addressof(expr)); + return *this ; + } + +#else + template<class Expr> + optional& operator= ( Expr const& expr ) + { + this->assign_expr(expr,boost::addressof(expr)); + return *this ; + } +#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES +#endif // !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION) + + // Copy-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 ; + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Move-assigns from another convertible optional<U> (converts && deep-moves the rhs value) + // Requires a valid conversion from U to T. + // Basic Guarantee: If T::T( U && ) throws, this is left UNINITIALIZED + template<class U> + optional& operator= ( optional<U> && rhs ) + { + this->assign(boost::move(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( static_cast<base const&>(rhs) ) ; + return *this ; + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Assigns from another optional<T> (deep-moves the rhs value) + optional& operator= ( optional && rhs ) + BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value) + { + this->assign( static_cast<base &&>(rhs) ) ; + return *this ; + } +#endif + + // 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 ; + } + +#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + // Assigns from a T (deep-moves the rhs value) + optional& operator= ( rval_reference_type val ) + { + optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>(); + this->assign( boost::move(val) ) ; + return *this ; + } +#endif + + // 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_ ) BOOST_NOEXCEPT + { + this->assign( none_ ) ; + return *this ; + } + +#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES) + // Constructs in-place + // upon exception *this is always uninitialized + template<class... Args> + void emplace ( Args&&... args ) + { + this->emplace_assign( boost::forward<Args>(args)... ); + } +#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) + template<class Arg> + void emplace ( Arg&& arg ) + { + this->emplace_assign( boost::forward<Arg>(arg) ); + } + + void emplace () + { + this->emplace_assign(); + } +#else + template<class Arg> + void emplace ( const Arg& arg ) + { + this->emplace_assign( arg ); + } + + template<class Arg> + void emplace ( Arg& arg ) + { + this->emplace_assign( arg ); + } + + void emplace () + { + this->emplace_assign(); + } +#endif + + void swap( optional & arg ) + BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value) + { + // allow for Koenig lookup + boost::swap(*this, arg); + } + + + // 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 +#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) + reference_const_type operator *() const& { return this->get() ; } + reference_type operator *() & { return this->get() ; } + reference_type_of_temporary_wrapper operator *() && { return base::types::move(this->get()) ; } +#else + reference_const_type operator *() const { return this->get() ; } + reference_type operator *() { return this->get() ; } +#endif // !defined BOOST_NO_CXX11_REF_QUALIFIERS + +#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) + reference_const_type value() const& + { + if (this->is_initialized()) + return this->get() ; + else + throw_exception(bad_optional_access()); + } + + reference_type value() & + { + if (this->is_initialized()) + return this->get() ; + else + throw_exception(bad_optional_access()); + } + + reference_type_of_temporary_wrapper value() && + { + if (this->is_initialized()) + return base::types::move(this->get()) ; + else + throw_exception(bad_optional_access()); + } + +#else + reference_const_type value() const + { + if (this->is_initialized()) + return this->get() ; + else + throw_exception(bad_optional_access()); + } + + reference_type value() + { + if (this->is_initialized()) + return this->get() ; + else + throw_exception(bad_optional_access()); + } +#endif + + +#ifndef BOOST_NO_CXX11_REF_QUALIFIERS + template <class U> + value_type value_or ( U&& v ) const& + { + if (this->is_initialized()) + return get(); + else + return boost::forward<U>(v); + } + + template <class U> + value_type value_or ( U&& v ) && + { + if (this->is_initialized()) + return base::types::move(get()); + else + return boost::forward<U>(v); + } +#elif !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES + template <class U> + value_type value_or ( U&& v ) const + { + if (this->is_initialized()) + return get(); + else + return boost::forward<U>(v); + } +#else + template <class U> + value_type value_or ( U const& v ) const + { + if (this->is_initialized()) + return get(); + else + return v; + } + + template <class U> + value_type value_or ( U& v ) const + { + if (this->is_initialized()) + return get(); + else + return v; + } +#endif + + +#ifndef BOOST_NO_CXX11_REF_QUALIFIERS + template <typename F> + value_type value_or_eval ( F f ) const& + { + if (this->is_initialized()) + return get(); + else + return f(); + } + + template <typename F> + value_type value_or_eval ( F f ) && + { + if (this->is_initialized()) + return base::types::move(get()); + else + return f(); + } +#else + template <typename F> + value_type value_or_eval ( F f ) const + { + if (this->is_initialized()) + return get(); + else + return f(); + } +#endif + + bool operator!() const BOOST_NOEXCEPT { return !this->is_initialized() ; } + + BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT() +} ; + +} // namespace boost + + +#endif // header guard |