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Diffstat (limited to '3rdParty/Boost/src/boost/variant/variant.hpp')
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1 files changed, 1862 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/variant/variant.hpp b/3rdParty/Boost/src/boost/variant/variant.hpp new file mode 100644 index 0000000..7e3c9e8 --- /dev/null +++ b/3rdParty/Boost/src/boost/variant/variant.hpp @@ -0,0 +1,1862 @@ +//----------------------------------------------------------------------------- +// boost variant/variant.hpp header file +// See http://www.boost.org for updates, documentation, and revision history. +//----------------------------------------------------------------------------- +// +// Copyright (c) 2002-2003 +// Eric Friedman, Itay Maman +// +// Distributed under 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) + +#ifndef BOOST_VARIANT_VARIANT_HPP +#define BOOST_VARIANT_VARIANT_HPP + +#include <cstddef> // for std::size_t +#include <new> // for placement new + +#if !defined(BOOST_NO_TYPEID) +#include <typeinfo> // for typeid, std::type_info +#endif // BOOST_NO_TYPEID + +#include "boost/variant/detail/config.hpp" +#include "boost/mpl/aux_/config/eti.hpp" +#include "boost/mpl/aux_/value_wknd.hpp" + +#include "boost/variant/variant_fwd.hpp" +#include "boost/variant/detail/backup_holder.hpp" +#include "boost/variant/detail/enable_recursive_fwd.hpp" +#include "boost/variant/detail/forced_return.hpp" +#include "boost/variant/detail/initializer.hpp" +#include "boost/variant/detail/make_variant_list.hpp" +#include "boost/variant/detail/over_sequence.hpp" +#include "boost/variant/detail/visitation_impl.hpp" + +#include "boost/variant/detail/generic_result_type.hpp" +#include "boost/variant/detail/has_nothrow_move.hpp" +#include "boost/variant/detail/move.hpp" + +#include "boost/detail/reference_content.hpp" +#include "boost/aligned_storage.hpp" +#include "boost/blank.hpp" +#include "boost/static_assert.hpp" +#include "boost/preprocessor/cat.hpp" +#include "boost/preprocessor/repeat.hpp" +#include "boost/type_traits/alignment_of.hpp" +#include "boost/type_traits/add_const.hpp" +#include "boost/type_traits/has_nothrow_constructor.hpp" +#include "boost/type_traits/has_nothrow_copy.hpp" +#include "boost/type_traits/is_const.hpp" +#include "boost/type_traits/is_same.hpp" +#include "boost/utility/enable_if.hpp" +#include "boost/variant/recursive_wrapper_fwd.hpp" +#include "boost/variant/static_visitor.hpp" + +#include "boost/mpl/eval_if.hpp" +#include "boost/mpl/begin_end.hpp" +#include "boost/mpl/bool.hpp" +#include "boost/mpl/empty.hpp" +#include "boost/mpl/find_if.hpp" +#include "boost/mpl/front.hpp" +#include "boost/mpl/identity.hpp" +#include "boost/mpl/if.hpp" +#include "boost/mpl/int.hpp" +#include "boost/mpl/is_sequence.hpp" +#include "boost/mpl/iterator_range.hpp" +#include "boost/mpl/iter_fold_if.hpp" +#include "boost/mpl/logical.hpp" +#include "boost/mpl/max_element.hpp" +#include "boost/mpl/next.hpp" +#include "boost/mpl/deref.hpp" +#include "boost/mpl/pair.hpp" +#include "boost/mpl/protect.hpp" +#include "boost/mpl/push_front.hpp" +#include "boost/mpl/same_as.hpp" +#include "boost/mpl/size_t.hpp" +#include "boost/mpl/sizeof.hpp" +#include "boost/mpl/transform.hpp" +#include "boost/mpl/assert.hpp" + +/////////////////////////////////////////////////////////////////////////////// +// Implementation Macros: +// +// BOOST_VARIANT_VISITATION_UNROLLING_LIMIT +// Defined in boost/variant/detail/visitation_impl.hpp. +// +// BOOST_VARIANT_MINIMIZE_SIZE +// When #defined, implementation employs all known means to minimize the +// size of variant obje cts. However, often unsuccessful due to alignment +// issues, and potentially harmful to runtime speed, so not enabled by +// default. (TODO: Investigate further.) + +#if defined(BOOST_VARIANT_MINIMIZE_SIZE) +# include <climits> // for SCHAR_MAX +# include "boost/mpl/eval_if.hpp" +# include "boost/mpl/equal_to.hpp" +# include "boost/mpl/identity.hpp" +# include "boost/mpl/int.hpp" +# include "boost/mpl/if.hpp" +# include "boost/mpl/less.hpp" +# include "boost/mpl/long.hpp" +# include "boost/mpl/O1_size.hpp" +#endif + + +namespace boost { + +namespace detail { namespace variant { + +/////////////////////////////////////////////////////////////////////////////// +// (detail) metafunction max_value +// +// Finds the maximum value of the unary metafunction F over Sequence. +// +template <typename Sequence, typename F> +struct max_value +{ +private: // helpers, for metafunction result (below) + + typedef typename mpl::transform1<Sequence, F>::type transformed_; + typedef typename mpl::max_element<transformed_ + + >::type max_it; + +public: // metafunction result + + typedef typename mpl::deref<max_it>::type + type; + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) metafunction find_fallback_type +// +// Provides a fallback (i.e., nothrow default-constructible) type from the +// specified sequence, or no_fallback_type if not found. +// +// This implementation is designed to prefer boost::blank over other potential +// fallback types, regardless of its position in the specified sequence. +// + +class no_fallback_type; + +struct find_fallback_type_pred +{ + template <typename Iterator> + struct apply + { + private: + typedef typename mpl::deref<Iterator>::type t_; + + public: + typedef mpl::not_< has_nothrow_constructor<t_> > type; + }; +}; + +template <typename Types> +struct find_fallback_type +{ +private: // helpers, for metafunction result (below) + + typedef typename mpl::end<Types>::type end_it; + + // [Find the first suitable fallback type...] + + typedef typename mpl::iter_fold_if< + Types + , mpl::int_<0>, mpl::protect< mpl::next<> > + , mpl::protect< find_fallback_type_pred > + >::type first_result_; + + typedef typename first_result_::first first_result_index; + typedef typename first_result_::second first_result_it; + + // [...now search the rest of the sequence for boost::blank...] + + typedef typename mpl::iter_fold_if< + mpl::iterator_range< first_result_it,end_it > + , first_result_index, mpl::protect< mpl::next<> > + , mpl::protect< mpl::not_same_as<boost::blank> > + >::type second_result_; + + typedef typename second_result_::second second_result_it; + +public: // metafunction result + + // [...and return the results of the search:] + typedef typename mpl::eval_if< + is_same< second_result_it,end_it > + , mpl::if_< + is_same< first_result_it,end_it > + , mpl::pair< no_fallback_type,no_fallback_type > + , first_result_ + > + , mpl::identity< second_result_ > + >::type type; + +}; + +#if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG) + +template<> +struct find_fallback_type<int> +{ + typedef mpl::pair< no_fallback_type,no_fallback_type > type; +}; + +#endif // BOOST_MPL_CFG_MSVC_60_ETI_BUG workaround + +/////////////////////////////////////////////////////////////////////////////// +// (detail) metafunction make_storage +// +// Provides an aligned storage type capable of holding any of the types +// specified in the given type-sequence. +// + +template <typename Types, typename NeverUsesBackupFlag> +struct make_storage +{ +private: // helpers, for metafunction result (below) + + typedef typename mpl::eval_if< + NeverUsesBackupFlag + , mpl::identity< Types > + , mpl::push_front< + Types, backup_holder<void*> + > + >::type types; + + typedef typename max_value< + types, mpl::sizeof_<mpl::_1> + >::type max_size; + +#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) + + typedef typename max_value< + types, alignment_of<mpl::_1> + >::type max_alignment; + +#else // borland + + // temporary workaround -- use maximal alignment + typedef mpl::size_t< -1 > max_alignment; + +#endif // borland workaround + +public: // metafunction result + +#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) + + typedef ::boost::aligned_storage< + BOOST_MPL_AUX_VALUE_WKND(max_size)::value + , BOOST_MPL_AUX_VALUE_WKND(max_alignment)::value + > type; + +#else // MSVC7 and below + + BOOST_STATIC_CONSTANT(std::size_t, msvc_max_size_c = max_size::value); + BOOST_STATIC_CONSTANT(std::size_t, msvc_max_alignment_c = max_alignment::value); + + typedef ::boost::aligned_storage< + msvc_max_size_c + , msvc_max_alignment_c + > type; + +#endif // MSVC workaround + +}; + +#if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG) + +template<> +struct make_storage<int,int> +{ + typedef int type; +}; + +#endif // BOOST_MPL_CFG_MSVC_60_ETI_BUG workaround + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class destroyer +// +// Internal visitor that destroys the value it visits. +// +struct destroyer + : public static_visitor<> +{ +public: // visitor interfaces + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(T& operand, int) const + { + operand.~T(); + +#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) || \ + BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) + operand; // suppresses warnings +#endif + + BOOST_VARIANT_AUX_RETURN_VOID; + } + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class template known_get +// +// Visitor that returns a reference to content of the specified type. +// +// Precondition: visited variant MUST contain logical content of type T. +// +template <typename T> +class known_get + : public static_visitor<T&> +{ + +#if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) + +public: // visitor interface + + T& operator()(T& operand) const + { + return operand; + } + + template <typename U> + T& operator()(U&) const + { + // logical error to be here: see precondition above + BOOST_ASSERT(false); + return ::boost::detail::variant::forced_return< T& >(); + } + +#else // MSVC6 + +private: // helpers, for visitor interface (below) + + T& execute(T& operand, mpl::true_) const + { + return operand; + } + + template <typename U> + T& execute(U& operand, mpl::false_) const + { + // logical error to be here: see precondition above + BOOST_ASSERT(false); + return ::boost::detail::variant::forced_return< T& >(); + } + +public: // visitor interface + + template <typename U> + T& operator()(U& operand) const + { + typedef typename is_same< U,T >::type + U_is_T; + + return execute(operand, U_is_T()); + } + +#endif // MSVC6 workaround + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class copy_into +// +// Internal visitor that copies the value it visits into the given buffer. +// +class copy_into + : public static_visitor<> +{ +private: // representation + + void* storage_; + +public: // structors + + explicit copy_into(void* storage) + : storage_(storage) + { + } + +public: // internal visitor interface + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const + { + new(storage_) T( operand.get() ); + BOOST_VARIANT_AUX_RETURN_VOID; + } + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const + { + new(storage_) T( operand.get() ); + BOOST_VARIANT_AUX_RETURN_VOID; + } + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(const T& operand, int) const + { + new(storage_) T(operand); + BOOST_VARIANT_AUX_RETURN_VOID; + } + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class assign_storage +// +// Internal visitor that assigns the given storage (which must be a +// constructed value of the same type) to the value it visits. +// +struct assign_storage + : public static_visitor<> +{ +private: // representation + + const void* rhs_storage_; + +public: // structors + + explicit assign_storage(const void* rhs_storage) + : rhs_storage_(rhs_storage) + { + } + +public: // internal visitor interfaces + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(backup_holder<T>& lhs_content, long) const + { + lhs_content.get() + = static_cast< const backup_holder<T>* >(rhs_storage_)->get(); + BOOST_VARIANT_AUX_RETURN_VOID; + } + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(const backup_holder<T>& lhs_content, long) const + { + lhs_content.get() + = static_cast< const backup_holder<T>* >(rhs_storage_)->get(); + BOOST_VARIANT_AUX_RETURN_VOID; + } + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(T& lhs_content, int) const + { + // NOTE TO USER : + // Compile error here indicates one of variant's bounded types does + // not meet the requirements of the Assignable concept. Thus, + // variant is not Assignable. + // + // Hint: Are any of the bounded types const-qualified or references? + // + lhs_content = *static_cast< const T* >(rhs_storage_); + BOOST_VARIANT_AUX_RETURN_VOID; + } + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class direct_assigner +// +// Generic static visitor that: if and only if the visited value is of the +// specified type, assigns the given value to the visited value and returns +// true; else returns false. +// +template <typename T> +class direct_assigner + : public static_visitor<bool> +{ +private: // representation + + const T& rhs_; + +public: // structors + + explicit direct_assigner(const T& rhs) + : rhs_(rhs) + { + } + +#if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) + +public: // visitor interface + + bool operator()(T& lhs) + { + lhs = rhs_; + return true; + } + + template <typename U> + bool operator()(U&) + { + return false; + } + +#else // MSVC6 + +private: // helpers, for visitor interface (below) + + bool execute(T& lhs, mpl::true_) + { + lhs = rhs_; + return true; + } + + template <typename U> + bool execute(U&, mpl::false_) + { + return false; + } + +public: // visitor interface + + template <typename U> + bool operator()(U& lhs) + { + typedef typename is_same<U,T>::type U_is_T; + return execute(lhs, U_is_T()); + } + +#endif // MSVC6 workaround + +#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) +private: + // silence MSVC warning C4512: assignment operator could not be generated + direct_assigner& operator= (direct_assigner const&); +#endif +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class backup_assigner +// +// Internal visitor that "assigns" the given value to the visited value, +// using backup to recover if the destroy-copy sequence fails. +// +// NOTE: This needs to be a friend of variant, as it needs access to +// indicate_which, indicate_backup_which, etc. +// +template <typename Variant, typename RhsT> +class backup_assigner + : public static_visitor<> +{ +private: // representation + + Variant& lhs_; + int rhs_which_; + const RhsT& rhs_content_; + +public: // structors + + backup_assigner(Variant& lhs, int rhs_which, const RhsT& rhs_content) + : lhs_(lhs) + , rhs_which_(rhs_which) + , rhs_content_(rhs_content) + { + } + +private: // helpers, for visitor interface (below) + + template <typename LhsT> + void backup_assign_impl( + LhsT& lhs_content + , mpl::true_// has_nothrow_move + ) + { + // Move lhs content to backup... + LhsT backup_lhs_content( + ::boost::detail::variant::move(lhs_content) + ); // nothrow + + // ...destroy lhs content... + lhs_content.~LhsT(); // nothrow + + try + { + // ...and attempt to copy rhs content into lhs storage: + new(lhs_.storage_.address()) RhsT(rhs_content_); + } + catch (...) + { + // In case of failure, restore backup content to lhs storage... + new(lhs_.storage_.address()) + LhsT( + ::boost::detail::variant::move(backup_lhs_content) + ); // nothrow + + // ...and rethrow: + throw; + } + + // In case of success, indicate new content type: + lhs_.indicate_which(rhs_which_); // nothrow + } + + template <typename LhsT> + void backup_assign_impl( + LhsT& lhs_content + , mpl::false_// has_nothrow_move + ) + { + // Backup lhs content... + LhsT* backup_lhs_ptr = new LhsT(lhs_content); + + // ...destroy lhs content... + lhs_content.~LhsT(); // nothrow + + try + { + // ...and attempt to copy rhs content into lhs storage: + new(lhs_.storage_.address()) RhsT(rhs_content_); + } + catch (...) + { + // In case of failure, copy backup pointer to lhs storage... + new(lhs_.storage_.address()) + backup_holder<LhsT>( backup_lhs_ptr ); // nothrow + + // ...indicate now using backup... + lhs_.indicate_backup_which( lhs_.which() ); // nothrow + + // ...and rethrow: + throw; + } + + // In case of success, indicate new content type... + lhs_.indicate_which(rhs_which_); // nothrow + + // ...and delete backup: + delete backup_lhs_ptr; // nothrow + } + +public: // visitor interface + + template <typename LhsT> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(LhsT& lhs_content, int) + { + typedef typename has_nothrow_move_constructor<LhsT>::type + nothrow_move; + + backup_assign_impl( lhs_content, nothrow_move() ); + + BOOST_VARIANT_AUX_RETURN_VOID; + } + +#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) +private: + // silence MSVC warning C4512: assignment operator could not be generated + backup_assigner& operator= (backup_assigner const&); +#endif +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class swap_with +// +// Visitor that swaps visited value with content of given variant. +// +// Precondition: Given variant MUST have same logical type as visited value. +// +template <typename Variant> +struct swap_with + : public static_visitor<> +{ +private: // representation + + Variant& toswap_; + +public: // structors + + explicit swap_with(Variant& toswap) + : toswap_(toswap) + { + } + +public: // internal visitor interfaces + + template <typename T> + void operator()(T& operand) const + { + // Since the precondition ensures types are same, get T... + known_get<T> getter; + T& other = toswap_.apply_visitor(getter); + + // ...and swap: + ::boost::detail::variant::move_swap( operand, other ); + } + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class reflect +// +// Generic static visitor that performs a typeid on the value it visits. +// + +#if !defined(BOOST_NO_TYPEID) + +class reflect + : public static_visitor<const std::type_info&> +{ +public: // visitor interfaces + + template <typename T> + const std::type_info& operator()(const T&) const + { + return typeid(T); + } + +}; + +#endif // BOOST_NO_TYPEID + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class comparer +// +// Generic static visitor that compares the content of the given lhs variant +// with the visited rhs content using Comp. +// +// Precondition: lhs.which() == rhs.which() +// +template <typename Variant, typename Comp> +class comparer + : public static_visitor<bool> +{ +private: // representation + + const Variant& lhs_; + +public: // structors + + explicit comparer(const Variant& lhs) + : lhs_(lhs) + { + } + +public: // visitor interfaces + + template <typename T> + bool operator()(const T& rhs_content) const + { + // Since the precondition ensures lhs and rhs types are same, get T... + known_get<const T> getter; + const T& lhs_content = lhs_.apply_visitor(getter); + + // ...and compare lhs and rhs contents: + return Comp()(lhs_content, rhs_content); + } + +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class equal_comp +// +// Generic function object compares lhs with rhs using operator==. +// +struct equal_comp +{ + template <typename T> + bool operator()(const T& lhs, const T& rhs) const + { + return lhs == rhs; + } +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class less_comp +// +// Generic function object compares lhs with rhs using operator<. +// +struct less_comp +{ + template <typename T> + bool operator()(const T& lhs, const T& rhs) const + { + return lhs < rhs; + } +}; + +/////////////////////////////////////////////////////////////////////////////// +// (detail) class template invoke_visitor +// +// Internal visitor that invokes the given visitor using: +// * for wrappers (e.g., recursive_wrapper), the wrapper's held value. +// * for all other values, the value itself. +// +template <typename Visitor> +class invoke_visitor +{ +private: // representation + + Visitor& visitor_; + +public: // visitor typedefs + + typedef typename Visitor::result_type + result_type; + +public: // structors + + explicit invoke_visitor(Visitor& visitor) + : visitor_(visitor) + { + } + +#if !defined(BOOST_NO_VOID_RETURNS) + +public: // internal visitor interfaces + + template <typename T> + result_type internal_visit(T& operand, int) + { + return visitor_(operand); + } + +# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564)) + template <typename T> + result_type internal_visit(const T& operand, int) + { + return visitor_(operand); + } +# endif + +#else // defined(BOOST_NO_VOID_RETURNS) + +private: // helpers, for internal visitor interfaces (below) + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + visit_impl(T& operand, mpl::false_) + { + return visitor_(operand); + } + + template <typename T> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + visit_impl(T& operand, mpl::true_) + { + visitor_(operand); + BOOST_VARIANT_AUX_RETURN_VOID; + } + +public: // internal visitor interfaces + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(T& operand, int) + { + typedef typename is_same<result_type, void>::type + has_void_result_type; + + return visit_impl(operand, has_void_result_type()); + } + +#endif // BOOST_NO_VOID_RETURNS) workaround + +public: // internal visitor interfaces, cont. + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(boost::recursive_wrapper<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(const boost::recursive_wrapper<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(boost::detail::reference_content<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(const boost::detail::reference_content<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(boost::detail::variant::backup_holder<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type) + internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) + { + return internal_visit( operand.get(), 1L ); + } + +#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) +private: + // silence MSVC warning C4512: assignment operator could not be generated + invoke_visitor& operator= (invoke_visitor const&); +#endif +}; + +}} // namespace detail::variant + +/////////////////////////////////////////////////////////////////////////////// +// class template variant (concept inspired by Andrei Alexandrescu) +// +// See docs and boost/variant/variant_fwd.hpp for more information. +// +template < + typename T0_ + , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(typename T) + > +class variant +{ +private: // helpers, for typedefs (below) + + typedef variant wknd_self_t; + + struct is_recursive_ + : detail::variant::is_recursive_flag<T0_> + { + }; + + typedef typename mpl::eval_if< + is_recursive_ + , T0_ + , mpl::identity< T0_ > + >::type unwrapped_T0_; + + struct is_sequence_based_ + : detail::variant::is_over_sequence<unwrapped_T0_> + { + }; + +#if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT) + +private: // helpers, for typedefs (below) + + typedef typename mpl::eval_if< + is_sequence_based_ + , unwrapped_T0_ // over_sequence<...>::type + , detail::variant::make_variant_list< + unwrapped_T0_ + , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T) + > + >::type specified_types; + + BOOST_STATIC_ASSERT(( + ::boost::mpl::not_< mpl::empty<specified_types> >::value + )); + + typedef typename mpl::eval_if< + is_recursive_ + , mpl::transform< + specified_types + , mpl::protect< + detail::variant::quoted_enable_recursive<wknd_self_t> + > + > + , mpl::identity< specified_types > + >::type recursive_enabled_types; + +public: // public typedefs + + typedef typename mpl::transform< + recursive_enabled_types + , unwrap_recursive<mpl::_1> + >::type types; + +private: // internal typedefs + + typedef typename mpl::transform< + recursive_enabled_types + , mpl::protect< detail::make_reference_content<> > + >::type internal_types; + + typedef typename mpl::front< + internal_types + >::type internal_T0; + +#else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT) + +private: // helpers, for typedefs (below) + + typedef unwrapped_T0_ T0; + + #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_) \ + typedef typename mpl::eval_if< \ + is_recursive_ \ + , detail::variant::enable_recursive< \ + BOOST_PP_CAT(T,N) \ + , wknd_self_t \ + > \ + , mpl::identity< BOOST_PP_CAT(T,N) > \ + >::type BOOST_PP_CAT(recursive_enabled_T,N); \ + /**/ + + BOOST_PP_REPEAT( + BOOST_VARIANT_LIMIT_TYPES + , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS + , _ + ) + + #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS + + #define BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS(z,N,_) \ + typedef typename unwrap_recursive< \ + BOOST_PP_CAT(recursive_enabled_T,N) \ + >::type BOOST_PP_CAT(public_T,N); \ + /**/ + + BOOST_PP_REPEAT( + BOOST_VARIANT_LIMIT_TYPES + , BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS + , _ + ) + + #undef BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS + +public: // public typedefs + + typedef typename detail::variant::make_variant_list< + BOOST_VARIANT_ENUM_PARAMS(public_T) + >::type types; + +private: // helpers, for internal typedefs (below) + + #define BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS(z,N,_) \ + typedef detail::make_reference_content< \ + BOOST_PP_CAT(recursive_enabled_T,N) \ + >::type BOOST_PP_CAT(internal_T,N); \ + /**/ + + BOOST_PP_REPEAT( + BOOST_VARIANT_LIMIT_TYPES + , BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS + , _ + ) + + #undef BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS + +private: // internal typedefs + + typedef typename detail::variant::make_variant_list< + BOOST_VARIANT_ENUM_PARAMS(internal_T) + >::type internal_types; + +private: // static precondition assertions + + // NOTE TO USER : + // variant< type-sequence > syntax is not supported on this compiler! + // + BOOST_MPL_ASSERT_NOT(( is_sequence_based_ )); + +#endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround + +private: // helpers, for representation (below) + + typedef typename detail::variant::find_fallback_type< + internal_types + >::type fallback_type_result_; + + typedef typename fallback_type_result_::first + fallback_type_index_; + typedef typename fallback_type_result_::second + fallback_type_; + + struct has_fallback_type_ + : mpl::not_< + is_same< fallback_type_, detail::variant::no_fallback_type > + > + { + }; + + typedef has_fallback_type_ + never_uses_backup_flag; + + typedef typename detail::variant::make_storage< + internal_types, never_uses_backup_flag + >::type storage_t; + +private: // helpers, for representation (below) + + // which_ on: + // * [0, size<internal_types>) indicates stack content + // * [-size<internal_types>, 0) indicates pointer to heap backup + // if which_ >= 0: + // * then which() -> which_ + // * else which() -> -(which_ + 1) + +#if !defined(BOOST_VARIANT_MINIMIZE_SIZE) + + typedef int which_t; + +#else // defined(BOOST_VARIANT_MINIMIZE_SIZE) + + // [if O1_size available, then attempt which_t size optimization...] + // [select signed char if fewer than SCHAR_MAX types, else signed int:] + typedef typename mpl::eval_if< + mpl::equal_to< mpl::O1_size<internal_types>, mpl::long_<-1> > + , mpl::identity< int > + , mpl::if_< + mpl::less< mpl::O1_size<internal_types>, mpl::int_<SCHAR_MAX> > + , signed char + , int + > + >::type which_t; + +#endif // BOOST_VARIANT_MINIMIZE_SIZE switch + +// representation -- private when possible +#if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) + private: +#else + public: +#endif + + which_t which_; + storage_t storage_; + + void indicate_which(int which) + { + which_ = static_cast<which_t>( which ); + } + + void indicate_backup_which(int which) + { + which_ = static_cast<which_t>( -(which + 1) ); + } + +private: // helpers, for queries (below) + + bool using_backup() const + { + return which_ < 0; + } + +public: // queries + + int which() const + { + // If using heap backup... + if (using_backup()) + // ...then return adjusted which_: + return -(which_ + 1); + + // Otherwise, return which_ directly: + return which_; + } + +private: // helpers, for structors (below) + + struct initializer + : BOOST_VARIANT_AUX_INITIALIZER_T( + recursive_enabled_types, recursive_enabled_T + ) + { + }; + + void destroy_content() + { + detail::variant::destroyer visitor; + this->internal_apply_visitor(visitor); + } + +public: // structors + + ~variant() + { + destroy_content(); + } + + variant() + { + // NOTE TO USER : + // Compile error from here indicates that the first bound + // type is not default-constructible, and so variant cannot + // support its own default-construction. + // + new( storage_.address() ) internal_T0(); + indicate_which(0); // zero is the index of the first bounded type + } + +private: // helpers, for structors, cont. (below) + + class convert_copy_into + : public static_visitor<int> + { + private: // representation + + void* storage_; + + public: // structors + + explicit convert_copy_into(void* storage) + : storage_(storage) + { + } + + public: // internal visitor interfaces (below) + + template <typename T> + int internal_visit(T& operand, int) const + { + // NOTE TO USER : + // Compile error here indicates one of the source variant's types + // cannot be unambiguously converted to the destination variant's + // types (or that no conversion exists). + // + return initializer::initialize(storage_, operand); + } + +# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564)) + template <typename T> + result_type internal_visit(const T& operand, int) const + { + return initializer::initialize(storage_, operand); + } +# endif + + template <typename T> + int internal_visit(boost::detail::reference_content<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + int internal_visit(const boost::detail::reference_content<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + int internal_visit(boost::recursive_wrapper<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + template <typename T> + int internal_visit(const boost::recursive_wrapper<T>& operand, long) const + { + return internal_visit( operand.get(), 1L ); + } + + }; + + friend class convert_copy_into; + +private: // helpers, for structors, below + + template <typename T> + void convert_construct( + T& operand + , int + , mpl::false_ = mpl::false_() // is_foreign_variant + ) + { + // NOTE TO USER : + // Compile error here indicates that the given type is not + // unambiguously convertible to one of the variant's types + // (or that no conversion exists). + // + indicate_which( + initializer::initialize( + storage_.address() + , operand + ) + ); + } + + template <typename Variant> + void convert_construct( + Variant& operand + , long + , mpl::true_// is_foreign_variant + ) + { + convert_copy_into visitor(storage_.address()); + indicate_which( + operand.internal_apply_visitor(visitor) + ); + } + + template <typename Variant> + void convert_construct_variant(Variant& operand) + { + // [Determine if the given variant is itself a bounded type, or if its + // content needs to be converted (i.e., it is a 'foreign' variant):] + // + + typedef typename mpl::find_if< + types + , is_same< + add_const<mpl::_1> + , const Variant + > + >::type found_it; + + typedef typename mpl::end<types>::type not_found; + typedef typename is_same< + found_it, not_found + >::type is_foreign_variant; + + // Convert construct from operand: + convert_construct( + operand, 1L + , is_foreign_variant() + ); + } + + template <BOOST_VARIANT_ENUM_PARAMS(typename U)> + void convert_construct( + boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand + , long + ) + { + convert_construct_variant(operand); + } + + template <BOOST_VARIANT_ENUM_PARAMS(typename U)> + void convert_construct( + const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand + , long + ) + { + convert_construct_variant(operand); + } + +public: // structors, cont. + +#if !defined(BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING) + + template <typename T> + variant(const T& operand) + { + convert_construct(operand, 1L); + } + + template <typename T> + variant(T& operand) + { + convert_construct(operand, 1L); + } + +#elif defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND) + + // For compilers that cannot distinguish between T& and const T& in + // template constructors, but do fully support SFINAE, we can workaround: + + template <typename T> + variant(const T& operand) + { + convert_construct(operand, 1L); + } + + template <typename T> + variant( + T& operand + , typename enable_if< + mpl::not_< is_const<T> > + , void + >::type* = 0 + ) + { + convert_construct(operand, 1L); + } + +#else // !defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND) + + // For compilers that cannot distinguish between T& and const T& in + // template constructors, and do NOT support SFINAE, we can't workaround: + + template <typename T> + variant(const T& operand) + { + convert_construct(operand, 1L); + } + +#endif // BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING workarounds + +public: // structors, cont. + + // [MSVC6 requires copy constructor appear after template constructors] + variant(const variant& operand) + { + // Copy the value of operand into *this... + detail::variant::copy_into visitor( storage_.address() ); + operand.internal_apply_visitor(visitor); + + // ...and activate the *this's primary storage on success: + indicate_which(operand.which()); + } + +private: // helpers, for modifiers (below) + +# if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) + template <typename Variant, typename RhsT> + friend class detail::variant::backup_assigner; +# endif + + // class assigner + // + // Internal visitor that "assigns" the visited value to the given variant + // by appropriate destruction and copy-construction. + // + + class assigner + : public static_visitor<> + { + private: // representation + + variant& lhs_; + int rhs_which_; + + public: // structors + + assigner(variant& lhs, int rhs_which) + : lhs_(lhs) + , rhs_which_(rhs_which) + { + } + + private: // helpers, for internal visitor interface (below) + + template <typename RhsT, typename B1, typename B2> + void assign_impl( + const RhsT& rhs_content + , mpl::true_// has_nothrow_copy + , B1// has_nothrow_move_constructor + , B2// has_fallback_type + ) + { + // Destroy lhs's content... + lhs_.destroy_content(); // nothrow + + // ...copy rhs content into lhs's storage... + new(lhs_.storage_.address()) + RhsT( rhs_content ); // nothrow + + // ...and indicate new content type: + lhs_.indicate_which(rhs_which_); // nothrow + } + + template <typename RhsT, typename B> + void assign_impl( + const RhsT& rhs_content + , mpl::false_// has_nothrow_copy + , mpl::true_// has_nothrow_move_constructor + , B// has_fallback_type + ) + { + // Attempt to make a temporary copy (so as to move it below)... + RhsT temp(rhs_content); + + // ...and upon success destroy lhs's content... + lhs_.destroy_content(); // nothrow + + // ...move the temporary copy into lhs's storage... + new(lhs_.storage_.address()) + RhsT( detail::variant::move(temp) ); // nothrow + + // ...and indicate new content type: + lhs_.indicate_which(rhs_which_); // nothrow + } + + template <typename RhsT> + void assign_impl( + const RhsT& rhs_content + , mpl::false_// has_nothrow_copy + , mpl::false_// has_nothrow_move_constructor + , mpl::true_// has_fallback_type + ) + { + // Destroy lhs's content... + lhs_.destroy_content(); // nothrow + + try + { + // ...and attempt to copy rhs's content into lhs's storage: + new(lhs_.storage_.address()) + RhsT( rhs_content ); + } + catch (...) + { + // In case of failure, default-construct fallback type in lhs's storage... + new (lhs_.storage_.address()) + fallback_type_; // nothrow + + // ...indicate construction of fallback type... + lhs_.indicate_which( + BOOST_MPL_AUX_VALUE_WKND(fallback_type_index_)::value + ); // nothrow + + // ...and rethrow: + throw; + } + + // In the event of success, indicate new content type: + lhs_.indicate_which(rhs_which_); // nothrow + } + + template <typename RhsT> + void assign_impl( + const RhsT& rhs_content + , mpl::false_// has_nothrow_copy + , mpl::false_// has_nothrow_move_constructor + , mpl::false_// has_fallback_type + ) + { + detail::variant::backup_assigner<wknd_self_t, RhsT> + visitor(lhs_, rhs_which_, rhs_content); + lhs_.internal_apply_visitor(visitor); + } + + public: // internal visitor interfaces + + template <typename RhsT> + BOOST_VARIANT_AUX_RETURN_VOID_TYPE + internal_visit(const RhsT& rhs_content, int) + { + typedef typename has_nothrow_copy<RhsT>::type + nothrow_copy; + typedef typename mpl::or_< // reduces compile-time + nothrow_copy + , detail::variant::has_nothrow_move_constructor<RhsT> + >::type nothrow_move_constructor; + + assign_impl( + rhs_content + , nothrow_copy() + , nothrow_move_constructor() + , has_fallback_type_() + ); + + BOOST_VARIANT_AUX_RETURN_VOID; + } + +#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) + private: + // silence MSVC warning C4512: assignment operator could not be generated + assigner& operator= (assigner const&); +#endif + }; + + friend class assigner; + + void variant_assign(const variant& rhs) + { + // If the contained types are EXACTLY the same... + if (which_ == rhs.which_) + { + // ...then assign rhs's storage to lhs's content: + detail::variant::assign_storage visitor(rhs.storage_.address()); + this->internal_apply_visitor(visitor); + } + else + { + // Otherwise, perform general (copy-based) variant assignment: + assigner visitor(*this, rhs.which()); + rhs.internal_apply_visitor(visitor); + } + } + +private: // helpers, for modifiers (below) + + template <typename T> + void assign(const T& rhs) + { + // If direct T-to-T assignment is not possible... + detail::variant::direct_assigner<T> direct_assign(rhs); + if (this->apply_visitor(direct_assign) == false) + { + // ...then convert rhs to variant and assign: + // + // While potentially inefficient, the following construction of a + // variant allows T as any type convertible to one of the bounded + // types without excessive code redundancy. + // + variant temp(rhs); + variant_assign( detail::variant::move(temp) ); + } + } + +public: // modifiers + + template <typename T> + variant& operator=(const T& rhs) + { + assign(rhs); + return *this; + } + + // [MSVC6 requires copy assign appear after templated operator=] + variant& operator=(const variant& rhs) + { + variant_assign(rhs); + return *this; + } + + void swap(variant& rhs) + { + // If the contained types are the same... + if (which() == rhs.which()) + { + // ...then swap the values directly: + detail::variant::swap_with<variant> visitor(rhs); + this->apply_visitor(visitor); + } + else + { + // ...otherwise, perform general variant swap: + variant tmp( detail::variant::move(rhs) ); + rhs = detail::variant::move(*this); + *this = detail::variant::move(tmp); + } + } + +public: // queries + + // + // NOTE: member which() defined above. + // + + bool empty() const + { + return false; + } + +#if !defined(BOOST_NO_TYPEID) + const std::type_info& type() const + { + detail::variant::reflect visitor; + return this->apply_visitor(visitor); + } +#endif + +public: // prevent comparison with foreign types + +#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) + +# define BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE \ + void + +#else // MSVC7 + + // + // MSVC7 gives error about return types for above being different than + // the true comparison operator overloads: + // + +# define BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE \ + bool + +#endif // MSVC7 workaround + + template <typename U> + BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE + operator==(const U&) const + { + BOOST_STATIC_ASSERT( false && sizeof(U) ); + } + + template <typename U> + BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE + operator<(const U&) const + { + BOOST_STATIC_ASSERT( false && sizeof(U) ); + } + +public: // comparison operators + + // [MSVC6 requires these operators appear after template operators] + + bool operator==(const variant& rhs) const + { + if (this->which() != rhs.which()) + return false; + + detail::variant::comparer< + variant, detail::variant::equal_comp + > visitor(*this); + return rhs.apply_visitor(visitor); + } + + bool operator<(const variant& rhs) const + { + // + // Dirk Schreib suggested this collating order. + // + + if (this->which() != rhs.which()) + return this->which() < rhs.which(); + + detail::variant::comparer< + variant, detail::variant::less_comp + > visitor(*this); + return rhs.apply_visitor(visitor); + } + +// helpers, for visitation support (below) -- private when possible +#if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) + + template < BOOST_VARIANT_ENUM_PARAMS(typename U) > + friend class variant; + +private: + +#else// defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) + +public: + +#endif// !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) + + template <typename Visitor, typename VoidPtrCV> + static + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE( + typename Visitor::result_type + ) + internal_apply_visitor_impl( + int internal_which + , int logical_which + , Visitor& visitor + , VoidPtrCV storage + ) + { + typedef mpl::int_<0> first_which; + typedef typename mpl::begin<internal_types>::type first_it; + typedef typename mpl::end<internal_types>::type last_it; + + typedef detail::variant::visitation_impl_step< + first_it, last_it + > first_step; + + return detail::variant::visitation_impl( + internal_which, logical_which + , visitor, storage, mpl::false_() + , never_uses_backup_flag() + , static_cast<first_which*>(0), static_cast<first_step*>(0) + ); + } + + template <typename Visitor> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE( + typename Visitor::result_type + ) + internal_apply_visitor(Visitor& visitor) + { + return internal_apply_visitor_impl( + which_, which(), visitor, storage_.address() + ); + } + + template <typename Visitor> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE( + typename Visitor::result_type + ) + internal_apply_visitor(Visitor& visitor) const + { + return internal_apply_visitor_impl( + which_, which(), visitor, storage_.address() + ); + } + +public: // visitation support + + template <typename Visitor> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE( + typename Visitor::result_type + ) + apply_visitor(Visitor& visitor) + { + detail::variant::invoke_visitor<Visitor> invoker(visitor); + return this->internal_apply_visitor(invoker); + } + + template <typename Visitor> + BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE( + typename Visitor::result_type + ) + apply_visitor(Visitor& visitor) const + { + detail::variant::invoke_visitor<Visitor> invoker(visitor); + return this->internal_apply_visitor(invoker); + } + +}; // class variant + +/////////////////////////////////////////////////////////////////////////////// +// metafunction make_variant_over +// +// See docs and boost/variant/variant_fwd.hpp for more information. +// +template <typename Types> +struct make_variant_over +{ +private: // precondition assertions + +#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) + BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value )); +#endif + +public: // metafunction result + + typedef variant< + detail::variant::over_sequence< Types > + > type; + +}; + +/////////////////////////////////////////////////////////////////////////////// +// function template swap +// +// Swaps two variants of the same type (i.e., identical specification). +// +template < BOOST_VARIANT_ENUM_PARAMS(typename T) > +inline void swap( + variant< BOOST_VARIANT_ENUM_PARAMS(T) >& lhs + , variant< BOOST_VARIANT_ENUM_PARAMS(T) >& rhs + ) +{ + lhs.swap(rhs); +} + +} // namespace boost + +// implementation additions + +#if !defined(BOOST_NO_IOSTREAM) +#include "boost/variant/detail/variant_io.hpp" +#endif // BOOST_NO_IOSTREAM + +#endif // BOOST_VARIANT_VARIANT_HPP |