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2453 lines
69 KiB
2453 lines
69 KiB
//----------------------------------------------------------------------------- |
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// boost variant/variant.hpp header file |
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// See http://www.boost.org for updates, documentation, and revision history. |
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//----------------------------------------------------------------------------- |
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// |
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// Copyright (c) 2002-2003 Eric Friedman, Itay Maman |
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// Copyright (c) 2012-2019 Antony Polukhin |
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// |
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// Distributed under the Boost Software License, Version 1.0. (See |
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// accompanying file LICENSE_1_0.txt or copy at |
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// http://www.boost.org/LICENSE_1_0.txt) |
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// Thanks to Adam Romanek for providing patches for exception-disabled env. |
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#ifndef BOOST_VARIANT_VARIANT_HPP |
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#define BOOST_VARIANT_VARIANT_HPP |
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#include <cstddef> // for std::size_t |
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#include <new> // for placement new |
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#include <boost/type_index.hpp> |
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#include <boost/variant/detail/config.hpp> |
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#include <boost/mpl/aux_/value_wknd.hpp> |
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#include <boost/variant/variant_fwd.hpp> |
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#include <boost/variant/detail/backup_holder.hpp> |
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#include <boost/variant/detail/enable_recursive_fwd.hpp> |
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#include <boost/variant/detail/forced_return.hpp> |
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#include <boost/variant/detail/initializer.hpp> |
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#include <boost/variant/detail/make_variant_list.hpp> |
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#include <boost/variant/detail/over_sequence.hpp> |
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#include <boost/variant/detail/visitation_impl.hpp> |
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#include <boost/variant/detail/hash_variant.hpp> |
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#include <boost/variant/detail/std_hash.hpp> |
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#include <boost/variant/detail/move.hpp> |
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#include <boost/detail/no_exceptions_support.hpp> |
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#include <boost/detail/reference_content.hpp> |
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#include <boost/aligned_storage.hpp> |
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#include <boost/blank.hpp> |
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#include <boost/integer/common_factor_ct.hpp> |
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#include <boost/static_assert.hpp> |
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#include <boost/preprocessor/cat.hpp> |
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#include <boost/preprocessor/repeat.hpp> |
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#include <boost/type_traits/alignment_of.hpp> |
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#include <boost/type_traits/add_const.hpp> |
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#include <boost/type_traits/has_nothrow_constructor.hpp> |
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#include <boost/type_traits/has_nothrow_copy.hpp> |
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#include <boost/type_traits/is_nothrow_move_assignable.hpp> |
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#include <boost/type_traits/is_nothrow_move_constructible.hpp> |
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#include <boost/type_traits/is_const.hpp> |
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#include <boost/type_traits/is_same.hpp> |
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#include <boost/type_traits/is_rvalue_reference.hpp> |
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#include <boost/type_traits/is_constructible.hpp> |
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#include <boost/type_traits/add_lvalue_reference.hpp> |
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#include <boost/utility/enable_if.hpp> |
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#include <boost/utility/declval.hpp> |
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#include <boost/variant/recursive_wrapper_fwd.hpp> |
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#include <boost/variant/static_visitor.hpp> |
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#include <boost/mpl/assert.hpp> |
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#include <boost/mpl/begin_end.hpp> |
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#include <boost/mpl/bool.hpp> |
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#include <boost/mpl/deref.hpp> |
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#include <boost/mpl/empty.hpp> |
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#include <boost/mpl/eval_if.hpp> |
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#include <boost/mpl/find_if.hpp> |
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#include <boost/mpl/fold.hpp> |
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#include <boost/mpl/front.hpp> |
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#include <boost/mpl/identity.hpp> |
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#include <boost/mpl/if.hpp> |
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#include <boost/mpl/insert_range.hpp> |
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#include <boost/mpl/int.hpp> |
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#include <boost/mpl/is_sequence.hpp> |
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#include <boost/mpl/iterator_range.hpp> |
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#include <boost/mpl/iter_fold_if.hpp> |
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#include <boost/mpl/list.hpp> |
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#include <boost/mpl/logical.hpp> |
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#include <boost/mpl/max_element.hpp> |
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#include <boost/mpl/next.hpp> |
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#include <boost/mpl/not.hpp> |
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#include <boost/mpl/pair.hpp> |
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#include <boost/mpl/protect.hpp> |
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#include <boost/mpl/push_front.hpp> |
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#include <boost/mpl/same_as.hpp> |
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#include <boost/mpl/size_t.hpp> |
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#include <boost/mpl/sizeof.hpp> |
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#include <boost/mpl/transform.hpp> |
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/////////////////////////////////////////////////////////////////////////////// |
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// Implementation Macros: |
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// |
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// BOOST_VARIANT_VISITATION_UNROLLING_LIMIT |
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// Defined in boost/variant/detail/visitation_impl.hpp. |
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// |
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// BOOST_VARIANT_MINIMIZE_SIZE |
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// When #defined, implementation employs all known means to minimize the |
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// size of variant obje cts. However, often unsuccessful due to alignment |
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// issues, and potentially harmful to runtime speed, so not enabled by |
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// default. (TODO: Investigate further.) |
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#if defined(BOOST_VARIANT_MINIMIZE_SIZE) |
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# include <climits> // for SCHAR_MAX |
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# include <boost/mpl/eval_if.hpp> |
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# include <boost/mpl/equal_to.hpp> |
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# include <boost/mpl/identity.hpp> |
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# include <boost/mpl/int.hpp> |
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# include <boost/mpl/if.hpp> |
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# include <boost/mpl/less.hpp> |
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# include <boost/mpl/long.hpp> |
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# include <boost/mpl/O1_size.hpp> |
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#endif |
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namespace boost { |
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namespace detail { namespace variant { |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction max_value |
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// |
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// Finds the maximum value of the unary metafunction F over Sequence. |
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// |
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template <typename Sequence, typename F> |
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struct max_value |
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{ |
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private: // helpers, for metafunction result (below) |
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typedef typename mpl::transform1<Sequence, F>::type transformed_; |
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typedef typename mpl::max_element<transformed_ |
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>::type max_it; |
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public: // metafunction result |
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typedef typename mpl::deref<max_it>::type |
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type; |
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}; |
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struct add_alignment |
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{ |
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template <typename State, typename Item> |
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struct apply |
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: mpl::size_t< |
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::boost::integer::static_lcm< |
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BOOST_MPL_AUX_VALUE_WKND(State)::value |
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, ::boost::alignment_of<Item>::value |
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>::value |
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> |
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{}; |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction find_fallback_type |
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// |
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// Provides a fallback (i.e., nothrow default-constructible) type from the |
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// specified sequence, or no_fallback_type if not found. |
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// |
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// This implementation is designed to prefer boost::blank over other potential |
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// fallback types, regardless of its position in the specified sequence. |
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// |
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class no_fallback_type; |
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struct find_fallback_type_pred |
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{ |
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template <typename Iterator> |
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struct apply |
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{ |
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private: |
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typedef typename mpl::deref<Iterator>::type t_; |
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public: |
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typedef mpl::not_< has_nothrow_constructor<t_> > type; |
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}; |
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}; |
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template <typename Types> |
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struct find_fallback_type |
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{ |
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private: // helpers, for metafunction result (below) |
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typedef typename mpl::end<Types>::type end_it; |
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// [Find the first suitable fallback type...] |
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typedef typename mpl::iter_fold_if< |
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Types |
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, mpl::int_<0>, mpl::protect< mpl::next<> > |
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, mpl::protect< find_fallback_type_pred > |
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>::type first_result_; |
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typedef typename first_result_::first first_result_index; |
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typedef typename first_result_::second first_result_it; |
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// [...now search the rest of the sequence for boost::blank...] |
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typedef typename mpl::iter_fold_if< |
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mpl::iterator_range< first_result_it,end_it > |
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, first_result_index, mpl::protect< mpl::next<> > |
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, mpl::protect< mpl::not_same_as<boost::blank> > |
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>::type second_result_; |
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typedef typename second_result_::second second_result_it; |
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public: // metafunction result |
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// [...and return the results of the search:] |
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typedef typename mpl::eval_if< |
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is_same< second_result_it,end_it > |
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, mpl::if_< |
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is_same< first_result_it,end_it > |
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, mpl::pair< no_fallback_type,no_fallback_type > |
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, first_result_ |
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> |
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, mpl::identity< second_result_ > |
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>::type type; |
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}; |
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#ifndef BOOST_NO_CXX11_NOEXCEPT |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction is_variant_move_noexcept_constructible |
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// |
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// Returns true_type if all the types are nothrow move constructible. |
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// |
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template <class Types> |
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struct is_variant_move_noexcept_constructible { |
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typedef typename boost::mpl::find_if< |
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Types, mpl::not_<boost::is_nothrow_move_constructible<boost::mpl::_1> > |
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>::type iterator_t; |
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typedef typename boost::mpl::end<Types>::type end_t; |
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typedef typename boost::is_same< |
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iterator_t, end_t |
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>::type type; |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction is_variant_move_noexcept_assignable |
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// |
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// Returns true_type if all the types are nothrow move constructible. |
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// |
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template <class Types> |
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struct is_variant_move_noexcept_assignable { |
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typedef typename boost::mpl::find_if< |
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Types, mpl::not_<boost::is_nothrow_move_assignable<boost::mpl::_1> > |
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>::type iterator_t; |
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typedef typename boost::mpl::end<Types>::type end_t; |
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typedef typename boost::is_same< |
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iterator_t, end_t |
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>::type type; |
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}; |
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#endif // BOOST_NO_CXX11_NOEXCEPT |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction is_variant_constructible_from |
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// |
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// Derives from true_type if at least one variant's type is constructible from T. |
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// |
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template <class T1, class T2> |
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struct is_constructible_ext: |
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boost::mpl::or_< |
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boost::is_constructible< |
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T1, |
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T2 |
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>, |
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boost::is_constructible< |
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T1, |
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typename boost::add_lvalue_reference<T2>::type |
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> |
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> |
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{}; |
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template <class T, class Types> |
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struct is_variant_constructible_from: |
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boost::mpl::not_< boost::is_same< |
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typename boost::mpl::find_if< |
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Types, |
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is_constructible_ext<boost::mpl::_1, T> |
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>::type, |
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typename boost::mpl::end<Types>::type |
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> > |
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{}; |
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template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> |
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struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types >: |
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boost::is_same< |
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typename boost::mpl::find_if< |
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typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::recursive_enabled_types, |
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mpl::not_< is_variant_constructible_from< boost::mpl::_1, Types> > |
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>::type, |
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typename boost::mpl::end< typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::recursive_enabled_types >::type |
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> |
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{}; |
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template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> |
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struct is_variant_constructible_from< const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& , Types >: |
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is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > |
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{}; |
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template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> |
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struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& , Types >: |
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is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > |
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{}; |
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
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template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> |
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struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>&& , Types >: |
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is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > |
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{}; |
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template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> |
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struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const && , Types >: |
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is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > |
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{}; |
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#endif // #ifndef BOOST_NO_CXX11_RVALUE_REFERENCE |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) metafunction make_storage |
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// |
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// Provides an aligned storage type capable of holding any of the types |
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// specified in the given type-sequence. |
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// |
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template <typename Types, typename NeverUsesBackupFlag> |
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struct make_storage |
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{ |
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private: // helpers, for metafunction result (below) |
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typedef typename mpl::eval_if< |
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NeverUsesBackupFlag |
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, mpl::identity< Types > |
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, mpl::push_front< |
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Types, backup_holder<void*> |
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> |
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>::type types; |
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typedef typename max_value< |
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types, mpl::sizeof_<mpl::_1> |
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>::type max_size; |
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#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) |
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typedef typename mpl::fold< |
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types |
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, mpl::size_t<1> |
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, add_alignment |
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>::type max_alignment; |
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#else // borland |
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// temporary workaround -- use maximal alignment |
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typedef mpl::size_t< -1 > max_alignment; |
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#endif // borland workaround |
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public: // metafunction result |
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typedef ::boost::aligned_storage< |
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BOOST_MPL_AUX_VALUE_WKND(max_size)::value |
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, BOOST_MPL_AUX_VALUE_WKND(max_alignment)::value |
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> type; |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class destroyer |
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// |
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// Internal visitor that destroys the value it visits. |
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// |
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struct destroyer |
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: public static_visitor<> |
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{ |
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public: // visitor interfaces |
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template <typename T> |
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void internal_visit(T& operand, int) const BOOST_NOEXCEPT |
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{ |
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operand.~T(); // must be noexcept |
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#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) || \ |
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BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) |
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(void)operand; // suppresses warnings |
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#endif |
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} |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class template known_get |
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// |
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// Visitor that returns a reference to content of the specified type. |
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// |
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// Precondition: visited variant MUST contain logical content of type T. |
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// |
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template <typename T> |
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class known_get |
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: public static_visitor<T&> |
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{ |
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public: // visitor interface |
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T& operator()(T& operand) const BOOST_NOEXCEPT |
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{ |
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return operand; |
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} |
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template <typename U> |
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T& operator()(U&) const |
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{ |
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// logical error to be here: see precondition above |
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return ::boost::detail::variant::forced_return< T& >(); |
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} |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class copy_into |
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// |
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// Internal visitor that copies the value it visits into the given buffer. |
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// |
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class copy_into |
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: public static_visitor<> |
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{ |
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private: // representation |
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void* storage_; |
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public: // structors |
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explicit copy_into(void* storage) BOOST_NOEXCEPT |
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: storage_(storage) |
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{ |
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} |
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public: // internal visitor interface |
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template <typename T> |
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void internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const |
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{ |
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new(storage_) T( operand.get() ); |
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} |
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template <typename T> |
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void internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const |
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{ |
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new(storage_) T( operand.get() ); |
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} |
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template <typename T> |
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void internal_visit(const T& operand, int) const |
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{ |
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new(storage_) T(operand); |
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} |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class move_into |
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// |
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// Internal visitor that moves the value it visits into the given buffer. |
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// |
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
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class move_into |
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: public static_visitor<> |
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{ |
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private: // representation |
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void* storage_; |
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public: // structors |
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explicit move_into(void* storage) BOOST_NOEXCEPT |
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: storage_(storage) |
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{ |
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} |
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public: // internal visitor interface |
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template <typename T> |
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void internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const |
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{ |
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new(storage_) T( ::boost::detail::variant::move(operand.get()) ); |
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} |
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template <typename T> |
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void internal_visit(T& operand, int) const BOOST_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(T(boost::declval<T>()))) |
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{ |
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new(storage_) T(::boost::detail::variant::move(operand)); |
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} |
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}; |
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#endif |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class assign_storage |
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// |
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// Internal visitor that assigns the given storage (which must be a |
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// constructed value of the same type) to the value it visits. |
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// |
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struct assign_storage |
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: public static_visitor<> |
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{ |
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private: // representation |
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const void* rhs_storage_; |
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public: // structors |
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explicit assign_storage(const void* rhs_storage) BOOST_NOEXCEPT |
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: rhs_storage_(rhs_storage) |
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{ |
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} |
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public: // internal visitor interfaces |
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|
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template <typename T> |
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void internal_visit(backup_holder<T>& lhs_content, long) const |
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{ |
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lhs_content.get() |
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= static_cast< const backup_holder<T>* >(rhs_storage_)->get(); |
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} |
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template <typename T> |
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void internal_visit(const backup_holder<T>& lhs_content, long) const |
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{ |
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lhs_content.get() |
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= static_cast< const backup_holder<T>* >(rhs_storage_)->get(); |
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} |
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template <typename T> |
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void internal_visit(T& lhs_content, int) const |
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{ |
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// NOTE TO USER : |
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// Compile error here indicates one of variant's bounded types does |
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// not meet the requirements of the Assignable concept. Thus, |
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// variant is not Assignable. |
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// |
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// Hint: Are any of the bounded types const-qualified or references? |
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// |
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lhs_content = *static_cast< const T* >(rhs_storage_); |
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} |
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}; |
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/////////////////////////////////////////////////////////////////////////////// |
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// (detail) class move_storage |
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// |
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// Internal visitor that moves the given storage (which must be a |
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// constructed value of the same type) to the value it visits. |
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// |
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struct move_storage |
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: public static_visitor<> |
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{ |
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private: // representation |
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void* rhs_storage_; |
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|
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public: // structors |
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|
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explicit move_storage(void* rhs_storage) BOOST_NOEXCEPT |
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: rhs_storage_(rhs_storage) |
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{ |
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} |
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|
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public: // internal visitor interfaces |
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|
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template <typename T> |
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void internal_visit(backup_holder<T>& lhs_content, long) const |
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{ |
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lhs_content.get() |
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= ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get()); |
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} |
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template <typename T> |
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void internal_visit(const backup_holder<T>& lhs_content, long) const |
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{ |
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lhs_content.get() |
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= ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get()); |
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} |
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template <typename T> |
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void internal_visit(T& lhs_content, int) const |
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{ |
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// NOTE TO USER : |
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// Compile error here indicates one of variant's bounded types does |
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// not meet the requirements of the Assignable concept. Thus, |
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// variant is not Assignable. |
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// |
|
// Hint: Are any of the bounded types const-qualified or references? |
|
// |
|
lhs_content = ::boost::detail::variant::move(*static_cast<T* >(rhs_storage_)); |
|
} |
|
|
|
}; |
|
|
|
/////////////////////////////////////////////////////////////////////////////// |
|
// (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) BOOST_NOEXCEPT |
|
: rhs_(rhs) |
|
{ |
|
} |
|
|
|
public: // visitor interface |
|
|
|
bool operator()(T& lhs) |
|
{ |
|
lhs = rhs_; |
|
return true; |
|
} |
|
|
|
template <typename U> |
|
bool operator()(U&) BOOST_NOEXCEPT |
|
{ |
|
return false; |
|
} |
|
|
|
#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 direct_mover |
|
// |
|
// Generic static visitor that: if and only if the visited value is of the |
|
// specified type, move assigns the given value to the visited value and returns |
|
// true; else returns false. |
|
// |
|
template <typename T> |
|
class direct_mover |
|
: public static_visitor<bool> |
|
{ |
|
private: // representation |
|
|
|
T& rhs_; |
|
|
|
public: // structors |
|
|
|
explicit direct_mover(T& rhs) BOOST_NOEXCEPT |
|
: rhs_(rhs) |
|
{ |
|
} |
|
|
|
public: // visitor interface |
|
|
|
bool operator()(T& lhs) |
|
{ |
|
lhs = ::boost::detail::variant::move(rhs_); |
|
return true; |
|
} |
|
|
|
template <typename U> |
|
bool operator()(U&) BOOST_NOEXCEPT |
|
{ |
|
return false; |
|
} |
|
|
|
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) |
|
private: |
|
// silence MSVC warning C4512: assignment operator could not be generated |
|
direct_mover& operator= (direct_mover 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> |
|
class backup_assigner |
|
: public static_visitor<> |
|
{ |
|
private: // representation |
|
|
|
Variant& lhs_; |
|
int rhs_which_; |
|
const void* rhs_content_; |
|
void (*copy_rhs_content_)(void*, const void*); |
|
|
|
public: // structors |
|
|
|
template<class RhsT> |
|
backup_assigner(Variant& lhs, int rhs_which, const RhsT& rhs_content) |
|
: lhs_(lhs) |
|
, rhs_which_(rhs_which) |
|
, rhs_content_(&rhs_content) |
|
, copy_rhs_content_(&construct_impl<RhsT>) |
|
{ |
|
} |
|
|
|
private: // helpers, for visitor interface (below) |
|
|
|
template<class RhsT> |
|
static void construct_impl(void* addr, const void* obj) |
|
{ |
|
new(addr) RhsT(*static_cast<const RhsT*>(obj)); |
|
} |
|
|
|
template <typename LhsT> |
|
void backup_assign_impl( |
|
backup_holder<LhsT>& lhs_content |
|
, mpl::false_ // is_nothrow_move_constructible |
|
, long |
|
) |
|
{ |
|
// Move lhs content to backup... |
|
backup_holder<LhsT> backup_lhs_content(0); |
|
backup_lhs_content.swap(lhs_content); // nothrow |
|
|
|
// ...destroy lhs content... |
|
lhs_content.~backup_holder<LhsT>(); // nothrow |
|
|
|
BOOST_TRY |
|
{ |
|
// ...and attempt to copy rhs content into lhs storage: |
|
copy_rhs_content_(lhs_.storage_.address(), rhs_content_); |
|
} |
|
BOOST_CATCH (...) |
|
{ |
|
// In case of failure, copy backup pointer to lhs storage... |
|
new(lhs_.storage_.address()) |
|
backup_holder<LhsT>( 0 ); // nothrow |
|
|
|
static_cast<backup_holder<LhsT>* >(lhs_.storage_.address()) |
|
->swap(backup_lhs_content); // nothrow |
|
|
|
// ...and rethrow: |
|
BOOST_RETHROW; |
|
} |
|
BOOST_CATCH_END |
|
|
|
// 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::true_ // is_nothrow_move_constructible |
|
, int |
|
) |
|
{ |
|
// Move lhs content to backup... |
|
LhsT backup_lhs_content( |
|
::boost::detail::variant::move(lhs_content) |
|
); // nothrow |
|
|
|
// ...destroy lhs content... |
|
lhs_content.~LhsT(); // nothrow |
|
|
|
BOOST_TRY |
|
{ |
|
// ...and attempt to copy rhs content into lhs storage: |
|
copy_rhs_content_(lhs_.storage_.address(), rhs_content_); |
|
} |
|
BOOST_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: |
|
BOOST_RETHROW; |
|
} |
|
BOOST_CATCH_END |
|
|
|
// 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_ // is_nothrow_move_constructible |
|
, int |
|
) |
|
{ |
|
// Backup lhs content... |
|
LhsT* backup_lhs_ptr = new LhsT(lhs_content); |
|
|
|
// ...destroy lhs content... |
|
lhs_content.~LhsT(); // nothrow |
|
|
|
BOOST_TRY |
|
{ |
|
// ...and attempt to copy rhs content into lhs storage: |
|
copy_rhs_content_(lhs_.storage_.address(), rhs_content_); |
|
} |
|
BOOST_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: |
|
BOOST_RETHROW; |
|
} |
|
BOOST_CATCH_END |
|
|
|
// 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> |
|
void internal_visit(LhsT& lhs_content, int) |
|
{ |
|
typedef typename is_nothrow_move_constructible<LhsT>::type |
|
nothrow_move; |
|
|
|
backup_assign_impl( lhs_content, nothrow_move(), 1L); |
|
} |
|
|
|
#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) BOOST_NOEXCEPT |
|
: 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 ); |
|
} |
|
|
|
private: |
|
swap_with& operator=(const swap_with&); |
|
|
|
}; |
|
|
|
/////////////////////////////////////////////////////////////////////////////// |
|
// (detail) class reflect |
|
// |
|
// Generic static visitor that performs a typeid on the value it visits. |
|
// |
|
|
|
class reflect |
|
: public static_visitor<const boost::typeindex::type_info&> |
|
{ |
|
public: // visitor interfaces |
|
|
|
template <typename T> |
|
const boost::typeindex::type_info& operator()(const T&) const BOOST_NOEXCEPT |
|
{ |
|
return boost::typeindex::type_id<T>().type_info(); |
|
} |
|
|
|
}; |
|
|
|
/////////////////////////////////////////////////////////////////////////////// |
|
// (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) BOOST_NOEXCEPT |
|
: lhs_(lhs) |
|
{ |
|
} |
|
|
|
public: // visitor interfaces |
|
|
|
template <typename T> |
|
bool operator()(T& rhs_content) const |
|
{ |
|
// Since the precondition ensures lhs and rhs types are same, get T... |
|
known_get<T> getter; |
|
const T& lhs_content = lhs_.apply_visitor(getter); |
|
|
|
// ...and compare lhs and rhs contents: |
|
return Comp()(lhs_content, rhs_content); |
|
} |
|
|
|
private: |
|
comparer& operator=(const comparer&); |
|
|
|
}; |
|
|
|
/////////////////////////////////////////////////////////////////////////////// |
|
// (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, bool MoveSemantics> |
|
class invoke_visitor |
|
{ |
|
private: // representation |
|
|
|
Visitor& visitor_; |
|
|
|
public: // visitor typedefs |
|
|
|
typedef typename Visitor::result_type |
|
result_type; |
|
|
|
public: // structors |
|
|
|
explicit invoke_visitor(Visitor& visitor) BOOST_NOEXCEPT |
|
: visitor_(visitor) |
|
{ |
|
} |
|
|
|
public: // internal visitor interfaces |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
//using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work |
|
template <typename T> |
|
typename enable_if_c<MoveSemantics && is_same<T, T>::value, result_type>::type internal_visit(T&& operand, int) |
|
{ |
|
return visitor_(::boost::move<T>(operand)); |
|
} |
|
|
|
//using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work |
|
template <typename T> |
|
typename disable_if_c<MoveSemantics && is_same<T, T>::value, result_type>::type internal_visit(T&& operand, int) |
|
{ |
|
return visitor_(operand); |
|
} |
|
|
|
#else |
|
|
|
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 //BORLAND |
|
|
|
#endif //RVALUE REFERENCES |
|
|
|
public: // internal visitor interfaces, cont. |
|
|
|
template <typename T> |
|
result_type internal_visit(boost::recursive_wrapper<T>& operand, long) |
|
{ |
|
return internal_visit( operand.get(), 1L ); |
|
} |
|
|
|
template <typename T> |
|
result_type internal_visit(const boost::recursive_wrapper<T>& operand, long) |
|
{ |
|
return internal_visit( operand.get(), 1L ); |
|
} |
|
|
|
template <typename T> |
|
result_type internal_visit(boost::detail::reference_content<T>& operand, long) |
|
{ |
|
return internal_visit( operand.get(), 1L ); |
|
} |
|
|
|
template <typename T> |
|
result_type internal_visit(const boost::detail::reference_content<T>& operand, long) |
|
{ |
|
return internal_visit( operand.get(), 1L ); |
|
} |
|
|
|
template <typename T> |
|
result_type internal_visit(boost::detail::variant::backup_holder<T>& operand, long) |
|
{ |
|
return internal_visit( operand.get(), 1L ); |
|
} |
|
|
|
template <typename T> |
|
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 |
|
)); |
|
|
|
public: // public typedefs |
|
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; // used by is_variant_constructible_from<> trait |
|
|
|
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; |
|
|
|
#ifndef BOOST_NO_CXX11_NOEXCEPT |
|
typedef typename detail::variant::is_variant_move_noexcept_constructible< |
|
internal_types |
|
> variant_move_noexcept_constructible; |
|
|
|
typedef typename detail::variant::is_variant_move_noexcept_assignable< |
|
internal_types |
|
> variant_move_noexcept_assignable; |
|
|
|
#endif |
|
|
|
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_arg) BOOST_NOEXCEPT |
|
{ |
|
which_ = static_cast<which_t>( which_arg ); |
|
} |
|
|
|
void indicate_backup_which(int which_arg) BOOST_NOEXCEPT |
|
{ |
|
which_ = static_cast<which_t>( -(which_arg + 1) ); |
|
} |
|
|
|
private: // helpers, for queries (below) |
|
|
|
bool using_backup() const BOOST_NOEXCEPT |
|
{ |
|
return which_ < 0; |
|
} |
|
|
|
public: // queries |
|
|
|
int which() const BOOST_NOEXCEPT |
|
{ |
|
// 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() BOOST_NOEXCEPT |
|
{ |
|
detail::variant::destroyer visitor; |
|
this->internal_apply_visitor(visitor); |
|
} |
|
|
|
public: // structors |
|
|
|
~variant() BOOST_NOEXCEPT |
|
{ |
|
destroy_content(); |
|
} |
|
|
|
variant() |
|
#if !(defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x5130)) |
|
BOOST_NOEXCEPT_IF(boost::has_nothrow_constructor<internal_T0>::value) |
|
#endif |
|
{ |
|
#ifdef _MSC_VER |
|
#pragma warning( push ) |
|
// behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized |
|
#pragma warning( disable : 4345 ) |
|
#endif |
|
// 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 |
|
#ifdef _MSC_VER |
|
#pragma warning( pop ) |
|
#endif |
|
} |
|
|
|
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) BOOST_NOEXCEPT |
|
: 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; |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
class convert_move_into |
|
: public static_visitor<int> |
|
{ |
|
private: // representation |
|
|
|
void* storage_; |
|
|
|
public: // structors |
|
|
|
explicit convert_move_into(void* storage) BOOST_NOEXCEPT |
|
: 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_, detail::variant::move(operand) ); |
|
} |
|
|
|
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_move_into; |
|
#endif |
|
|
|
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 |
|
) |
|
); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <typename T> |
|
typename boost::enable_if<boost::is_rvalue_reference<T&&> >::type 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() |
|
, detail::variant::move(operand) |
|
) |
|
); |
|
} |
|
#endif |
|
|
|
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) |
|
); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <typename Variant> |
|
typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct( |
|
Variant&& operand |
|
, long |
|
, mpl::true_// is_foreign_variant |
|
) |
|
{ |
|
convert_move_into visitor(storage_.address()); |
|
indicate_which( |
|
operand.internal_apply_visitor(visitor) |
|
); |
|
} |
|
#endif |
|
|
|
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() |
|
); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <typename Variant> |
|
typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type 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 move construct from operand: |
|
convert_construct( |
|
detail::variant::move(operand), 1L |
|
, is_foreign_variant() |
|
); |
|
} |
|
#endif |
|
|
|
template <BOOST_VARIANT_ENUM_PARAMS(typename U)> |
|
typename boost::enable_if<mpl::or_< |
|
boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, |
|
boost::detail::variant::is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&, internal_types> |
|
> >::type convert_construct( |
|
boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand |
|
, long |
|
) |
|
{ |
|
convert_construct_variant(operand); |
|
} |
|
|
|
template <BOOST_VARIANT_ENUM_PARAMS(typename U)> |
|
typename boost::enable_if<mpl::or_< |
|
boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, |
|
boost::detail::variant::is_variant_constructible_from<const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&, internal_types> |
|
> >::type convert_construct( |
|
const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand |
|
, long |
|
) |
|
{ |
|
convert_construct_variant(operand); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <BOOST_VARIANT_ENUM_PARAMS(typename U)> |
|
typename boost::enable_if<mpl::or_< |
|
boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, |
|
boost::detail::variant::is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&&, internal_types> |
|
> >::type convert_construct( |
|
boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&& operand |
|
, long |
|
) |
|
{ |
|
convert_construct_variant( detail::variant::move(operand) ); |
|
} |
|
#endif |
|
|
|
public: // structors, cont. |
|
|
|
template <typename T> |
|
variant(const T& operand, |
|
typename boost::enable_if<mpl::or_< |
|
mpl::and_< |
|
mpl::not_< boost::is_same<T, variant> >, |
|
boost::detail::variant::is_variant_constructible_from<const T&, internal_types> |
|
>, |
|
boost::is_same<T, boost::recursive_variant_> > >::type* = 0) |
|
{ |
|
convert_construct(operand, 1L); |
|
} |
|
|
|
template <typename T> |
|
variant( |
|
T& operand |
|
, typename boost::enable_if<mpl::or_< |
|
mpl::and_< |
|
mpl::not_< is_const<T> >, |
|
mpl::not_< boost::is_same<T, variant> >, |
|
boost::detail::variant::is_variant_constructible_from<T&, internal_types> |
|
>, |
|
boost::is_same<T, boost::recursive_variant_> > >::type* = 0 |
|
) |
|
{ |
|
convert_construct(operand, 1L); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <class T> |
|
variant(T&& operand, |
|
typename boost::enable_if<mpl::or_< |
|
mpl::and_< |
|
boost::is_rvalue_reference<T&&>, |
|
mpl::not_< boost::is_const<T> >, |
|
mpl::not_< boost::is_same<T, variant> >, |
|
boost::detail::variant::is_variant_constructible_from<T&&, internal_types> |
|
>, |
|
boost::is_same<T, boost::recursive_variant_> > >::type* = 0) |
|
{ |
|
convert_construct( detail::variant::move(operand), 1L); |
|
} |
|
#endif |
|
|
|
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()); |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
variant(variant&& operand) BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value) |
|
{ |
|
// Move the value of operand into *this... |
|
detail::variant::move_into visitor( storage_.address() ); |
|
operand.internal_apply_visitor(visitor); |
|
|
|
// ...and activate the *this's primary storage on success: |
|
indicate_which(operand.which()); |
|
} |
|
#endif |
|
|
|
private: // helpers, for modifiers (below) |
|
|
|
# if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) |
|
template <typename Variant> |
|
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<> |
|
{ |
|
protected: // representation |
|
|
|
variant& lhs_; |
|
const int rhs_which_; |
|
|
|
public: // structors |
|
|
|
assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT |
|
: lhs_(lhs) |
|
, rhs_which_(rhs_which) |
|
{ |
|
} |
|
|
|
protected: // 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 // is_nothrow_move_constructible |
|
, B2 // has_fallback_type |
|
) const BOOST_NOEXCEPT |
|
{ |
|
// 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_ // is_nothrow_move_constructible |
|
, B // has_fallback_type |
|
) const |
|
{ |
|
// 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 |
|
} |
|
|
|
void construct_fallback() const BOOST_NOEXCEPT { |
|
// 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 |
|
} |
|
|
|
template <typename RhsT> |
|
void assign_impl( |
|
const RhsT& rhs_content |
|
, mpl::false_ // has_nothrow_copy |
|
, mpl::false_ // is_nothrow_move_constructible |
|
, mpl::true_ // has_fallback_type |
|
) const |
|
{ |
|
// Destroy lhs's content... |
|
lhs_.destroy_content(); // nothrow |
|
|
|
BOOST_TRY |
|
{ |
|
// ...and attempt to copy rhs's content into lhs's storage: |
|
new(lhs_.storage_.address()) |
|
RhsT( rhs_content ); |
|
} |
|
BOOST_CATCH (...) |
|
{ |
|
construct_fallback(); |
|
|
|
// ...and rethrow: |
|
BOOST_RETHROW; |
|
} |
|
BOOST_CATCH_END |
|
|
|
// 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_ // is_nothrow_move_constructible |
|
, mpl::false_ // has_fallback_type |
|
) const |
|
{ |
|
detail::variant::backup_assigner<wknd_self_t> |
|
visitor(lhs_, rhs_which_, rhs_content); |
|
lhs_.internal_apply_visitor(visitor); |
|
} |
|
|
|
public: // internal visitor interfaces |
|
|
|
template <typename RhsT> |
|
void internal_visit(const RhsT& rhs_content, int) const |
|
{ |
|
typedef typename has_nothrow_copy<RhsT>::type |
|
nothrow_copy; |
|
typedef typename mpl::or_< // reduces compile-time |
|
nothrow_copy |
|
, is_nothrow_move_constructible<RhsT> |
|
>::type nothrow_move_constructor; |
|
|
|
assign_impl( |
|
rhs_content |
|
, nothrow_copy() |
|
, nothrow_move_constructor() |
|
, has_fallback_type_() |
|
); |
|
} |
|
|
|
#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; |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
// class move_assigner |
|
// |
|
// Internal visitor that "move assigns" the visited value to the given variant |
|
// by appropriate destruction and move-construction. |
|
// |
|
|
|
class move_assigner |
|
: public assigner |
|
{ |
|
public: // structors |
|
|
|
move_assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT |
|
: assigner(lhs, rhs_which) |
|
{ |
|
} |
|
|
|
private: // helpers, for internal visitor interface (below) |
|
|
|
template <typename RhsT, typename B2> |
|
void assign_impl( |
|
RhsT& rhs_content |
|
, mpl::true_ // has_nothrow_copy |
|
, mpl::false_ // is_nothrow_move_constructible |
|
, B2 // has_fallback_type |
|
) const BOOST_NOEXCEPT |
|
{ |
|
assigner::assign_impl(rhs_content, mpl::true_(), mpl::false_(), B2()); |
|
} |
|
|
|
template <typename RhsT, typename B, typename B2> |
|
void assign_impl( |
|
RhsT& rhs_content |
|
, B // has_nothrow_copy |
|
, mpl::true_ // is_nothrow_move_constructible |
|
, B2 // has_fallback_type |
|
) const BOOST_NOEXCEPT |
|
{ |
|
// ...destroy lhs's content... |
|
assigner::lhs_.destroy_content(); // nothrow |
|
|
|
// ...move the rhs_content into lhs's storage... |
|
new(assigner::lhs_.storage_.address()) |
|
RhsT( detail::variant::move(rhs_content) ); // nothrow |
|
|
|
// ...and indicate new content type: |
|
assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow |
|
} |
|
|
|
template <typename RhsT> |
|
void assign_impl( |
|
RhsT& rhs_content |
|
, mpl::false_ // has_nothrow_copy |
|
, mpl::false_ // is_nothrow_move_constructible |
|
, mpl::true_ // has_fallback_type |
|
) const |
|
{ |
|
// Destroy lhs's content... |
|
assigner::lhs_.destroy_content(); // nothrow |
|
|
|
BOOST_TRY |
|
{ |
|
// ...and attempt to copy rhs's content into lhs's storage: |
|
new(assigner::lhs_.storage_.address()) |
|
RhsT( detail::variant::move(rhs_content) ); |
|
} |
|
BOOST_CATCH (...) |
|
{ |
|
assigner::construct_fallback(); |
|
|
|
// ...and rethrow: |
|
BOOST_RETHROW; |
|
} |
|
BOOST_CATCH_END |
|
|
|
// In the event of success, indicate new content type: |
|
assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow |
|
} |
|
|
|
template <typename RhsT> |
|
void assign_impl( |
|
RhsT& rhs_content |
|
, mpl::false_ // has_nothrow_copy |
|
, mpl::false_ // is_nothrow_move_constructible |
|
, mpl::false_ // has_fallback_type |
|
) const |
|
{ |
|
assigner::assign_impl(rhs_content, mpl::false_(), mpl::false_(), mpl::false_()); |
|
} |
|
|
|
public: // internal visitor interfaces |
|
|
|
template <typename RhsT> |
|
void internal_visit(RhsT& rhs_content, int) const |
|
{ |
|
typedef typename is_nothrow_move_constructible<RhsT>::type |
|
nothrow_move_constructor; |
|
typedef typename mpl::or_< // reduces compile-time |
|
nothrow_move_constructor |
|
, has_nothrow_copy<RhsT> |
|
>::type nothrow_copy; |
|
|
|
assign_impl( |
|
rhs_content |
|
, nothrow_copy() |
|
, nothrow_move_constructor() |
|
, has_fallback_type_() |
|
); |
|
} |
|
|
|
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) |
|
private: |
|
// silence MSVC warning C4512: assignment operator could not be generated |
|
move_assigner& operator= (move_assigner const&); |
|
#endif |
|
}; |
|
|
|
friend class move_assigner; |
|
#endif // BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
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); |
|
} |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
void variant_assign(variant&& rhs) |
|
{ |
|
// If the contained types are EXACTLY the same... |
|
if (which_ == rhs.which_) |
|
{ |
|
// ...then move rhs's storage to lhs's content: |
|
detail::variant::move_storage visitor(rhs.storage_.address()); |
|
this->internal_apply_visitor(visitor); |
|
} |
|
else |
|
{ |
|
// Otherwise, perform general (move-based) variant assignment: |
|
move_assigner visitor(*this, rhs.which()); |
|
rhs.internal_apply_visitor(visitor); |
|
} |
|
} |
|
#endif // BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
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) ); |
|
} |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <typename T> |
|
void move_assign(T&& rhs) |
|
{ |
|
// If direct T-to-T move assignment is not possible... |
|
detail::variant::direct_mover<T> direct_move(rhs); |
|
if (this->apply_visitor(direct_move) == 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( detail::variant::move(rhs) ); |
|
variant_assign( detail::variant::move(temp) ); |
|
} |
|
} |
|
#endif // BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
public: // modifiers |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
template <class T> |
|
typename boost::enable_if< |
|
boost::mpl::and_< |
|
boost::is_rvalue_reference<T&&>, |
|
mpl::not_< boost::is_const<T> >, |
|
boost::detail::variant::is_variant_constructible_from<T&&, internal_types> |
|
>, |
|
variant& |
|
>::type operator=(T&& rhs) |
|
{ |
|
move_assign( detail::variant::move(rhs) ); |
|
return *this; |
|
} |
|
#endif // BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
template <typename T> |
|
typename boost::enable_if< |
|
mpl::or_< |
|
boost::is_same<T, variant>, |
|
boost::detail::variant::is_variant_constructible_from<const T&, internal_types> |
|
>, |
|
variant& |
|
>::type 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; |
|
} |
|
|
|
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
|
variant& operator=(variant&& rhs) |
|
#if !defined(__GNUC__) || (__GNUC__ != 4) || (__GNUC_MINOR__ > 6) || defined(__clang__) |
|
BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value && variant_move_noexcept_assignable::type::value) |
|
#endif |
|
{ |
|
variant_assign( detail::variant::move(rhs) ); |
|
return *this; |
|
} |
|
#endif // BOOST_NO_CXX11_RVALUE_REFERENCES |
|
|
|
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 BOOST_NOEXCEPT |
|
{ |
|
return false; |
|
} |
|
|
|
const boost::typeindex::type_info& type() const |
|
{ |
|
detail::variant::reflect visitor; |
|
return this->apply_visitor(visitor); |
|
} |
|
|
|
public: // prevent comparison with foreign types |
|
|
|
template <typename U> |
|
void operator==(const U&) const |
|
{ |
|
BOOST_STATIC_ASSERT( false && sizeof(U) ); |
|
} |
|
|
|
template <typename U> |
|
void operator<(const U&) const |
|
{ |
|
BOOST_STATIC_ASSERT( false && sizeof(U) ); |
|
} |
|
|
|
template <typename U> |
|
void operator!=(const U&) const |
|
{ |
|
BOOST_STATIC_ASSERT( false && sizeof(U) ); |
|
} |
|
|
|
template <typename U> |
|
void operator>(const U&) const |
|
{ |
|
BOOST_STATIC_ASSERT( false && sizeof(U) ); |
|
} |
|
|
|
template <typename U> |
|
void operator<=(const U&) const |
|
{ |
|
BOOST_STATIC_ASSERT( false && sizeof(U) ); |
|
} |
|
|
|
template <typename U> |
|
void 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); |
|
} |
|
|
|
/////////////////////////////////////////////////////////////////////////////// |
|
// comparison operators != > <= >= |
|
inline bool operator!=(const variant& rhs) const |
|
{ |
|
return !(*this == rhs); |
|
} |
|
|
|
inline bool operator>(const variant& rhs) const |
|
{ |
|
return rhs < *this; |
|
} |
|
|
|
inline bool operator<=(const variant& rhs) const |
|
{ |
|
return !(*this > rhs); |
|
} |
|
|
|
inline bool operator>=(const variant& rhs) const |
|
{ |
|
return !(*this < rhs); |
|
} |
|
|
|
// 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> |
|
BOOST_FORCEINLINE static 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_FORCEINLINE typename Visitor::result_type |
|
internal_apply_visitor(Visitor& visitor) |
|
{ |
|
return internal_apply_visitor_impl( |
|
which_, which(), visitor, storage_.address() |
|
); |
|
} |
|
|
|
template <typename Visitor> |
|
BOOST_FORCEINLINE typename Visitor::result_type |
|
internal_apply_visitor(Visitor& visitor) const |
|
{ |
|
return internal_apply_visitor_impl( |
|
which_, which(), visitor, storage_.address() |
|
); |
|
} |
|
|
|
public: // visitation support |
|
|
|
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
|
|
|
template <typename Visitor> |
|
typename Visitor::result_type |
|
apply_visitor(Visitor& visitor) && |
|
{ |
|
detail::variant::invoke_visitor<Visitor, true> invoker(visitor); |
|
return this->internal_apply_visitor(invoker); |
|
} |
|
|
|
template <typename Visitor> |
|
typename Visitor::result_type |
|
apply_visitor(Visitor& visitor) const&& |
|
{ |
|
detail::variant::invoke_visitor<Visitor, true> invoker(visitor); |
|
return this->internal_apply_visitor(invoker); |
|
} |
|
|
|
#endif |
|
|
|
template <typename Visitor> |
|
typename Visitor::result_type |
|
apply_visitor(Visitor& visitor) |
|
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
|
& |
|
#endif |
|
{ |
|
detail::variant::invoke_visitor<Visitor, false> invoker(visitor); |
|
return this->internal_apply_visitor(invoker); |
|
} |
|
|
|
template <typename Visitor> |
|
typename Visitor::result_type |
|
apply_visitor(Visitor& visitor) const |
|
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
|
& |
|
#endif |
|
{ |
|
detail::variant::invoke_visitor<Visitor, false> 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 |
|
|
|
BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value )); |
|
typedef typename boost::mpl::insert_range< |
|
boost::mpl::list<> |
|
, boost::mpl::end< boost::mpl::list<> >::type |
|
, Types |
|
>::type copied_sequence_t; |
|
|
|
public: // metafunction result |
|
|
|
typedef variant< |
|
detail::variant::over_sequence<copied_sequence_t> |
|
> 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
|
|
|