--- /dev/null
+/*=============================================================================
+ Copyright (c) 2001-2011 Hartmut Kaiser
+ Copyright (c) 2001-2011 Joel de Guzman
+
+ Distributed under the Boost Software License, Version 1.0. (See accompanying
+ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#if !defined(SPIRIT_PASS_CONTAINER_MAR_15_2009_0114PM)
+#define SPIRIT_PASS_CONTAINER_MAR_15_2009_0114PM
+
+#if defined(_MSC_VER)
+#pragma once
+#endif
+
+#include <boost/spirit/home/karma/detail/attributes.hpp>
+#include <boost/spirit/home/support/container.hpp>
+#include <boost/spirit/home/support/handles_container.hpp>
+#include <boost/spirit/home/support/detail/hold_any.hpp>
+#include <boost/type_traits/is_base_of.hpp>
+#include <boost/type_traits/is_convertible.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/and.hpp>
+#include <boost/mpl/or.hpp>
+#include <boost/preprocessor/cat.hpp>
+#include <boost/preprocessor/repetition/repeat.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/fusion/include/deduce_sequence.hpp>
+
+#include <boost/mpl/print.hpp>
+
+namespace boost { namespace spirit { namespace karma { namespace detail
+{
+ // Helper meta-function allowing to evaluate weak substitutability and
+ // negate the result if the predicate (Sequence) is not true
+ template <typename Sequence, typename Attribute, typename ValueType>
+ struct negate_weak_substitute_if_not
+ : mpl::if_<
+ Sequence
+ , typename traits::is_weak_substitute<Attribute, ValueType>::type
+ , typename mpl::not_<
+ traits::is_weak_substitute<Attribute, ValueType>
+ >::type>
+ {};
+
+ // pass_through_container: utility to check decide whether a provided
+ // container attribute needs to be passed through to the current component
+ // or of we need to split the container by passing along instances of its
+ // value type
+
+ // if the expected attribute of the current component is neither a Fusion
+ // sequence nor a container, we will pass through the provided container
+ // only if its value type is not compatible with the component
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence, typename Enable = void>
+ struct pass_through_container_base
+ : negate_weak_substitute_if_not<Sequence, ValueType, Attribute>
+ {};
+
+ // Specialization for fusion sequences, in this case we check whether all
+ // the types in the sequence are convertible to the lhs attribute.
+ //
+ // We return false if the rhs attribute itself is a fusion sequence, which
+ // is compatible with the LHS sequence (we want to pass through this
+ // attribute without it being split apart).
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence = mpl::true_>
+ struct not_compatible_element
+ : mpl::and_<
+ negate_weak_substitute_if_not<Sequence, Container, Attribute>
+ , negate_weak_substitute_if_not<Sequence, ValueType, Attribute> >
+ {};
+
+ // If the value type of the container is not a Fusion sequence, we pass
+ // through the container if each of the elements of the Attribute
+ // sequence is compatible with either the container or its value type.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence
+ , bool IsSequence = fusion::traits::is_sequence<ValueType>::value>
+ struct pass_through_container_fusion_sequence
+ {
+ typedef typename mpl::find_if<
+ Attribute, not_compatible_element<Container, ValueType, mpl::_1>
+ >::type iter;
+ typedef typename mpl::end<Attribute>::type end;
+
+ typedef typename is_same<iter, end>::type type;
+ };
+
+ // If both, the Attribute and the value type of the provided container
+ // are Fusion sequences, we pass the container only if the two
+ // sequences are not compatible.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container_fusion_sequence<
+ Container, ValueType, Attribute, Sequence, true>
+ {
+ typedef typename mpl::find_if<
+ Attribute
+ , not_compatible_element<Container, ValueType, mpl::_1, Sequence>
+ >::type iter;
+ typedef typename mpl::end<Attribute>::type end;
+
+ typedef typename is_same<iter, end>::type type;
+ };
+
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container_base<Container, ValueType, Attribute
+ , Sequence
+ , typename enable_if<fusion::traits::is_sequence<Attribute> >::type>
+ : pass_through_container_fusion_sequence<
+ Container, ValueType, Attribute, Sequence>
+ {};
+
+ // Specialization for containers
+ //
+ // If the value type of the attribute of the current component is not
+ // a Fusion sequence, we have to pass through the provided container if
+ // both are compatible.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence, typename AttributeValueType
+ , bool IsSequence = fusion::traits::is_sequence<AttributeValueType>::value>
+ struct pass_through_container_container
+ : mpl::or_<
+ traits::is_weak_substitute<Container, Attribute>
+ , traits::is_weak_substitute<Container, AttributeValueType> >
+ {};
+
+ // If the value type of the exposed container attribute is a Fusion
+ // sequence, we use the already existing logic for those.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence, typename AttributeValueType>
+ struct pass_through_container_container<
+ Container, ValueType, Attribute, Sequence, AttributeValueType, true>
+ : pass_through_container_fusion_sequence<
+ Container, ValueType, AttributeValueType, Sequence>
+ {};
+
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container_base<Container, ValueType, Attribute
+ , Sequence
+ , typename enable_if<traits::is_container<Attribute> >::type>
+ : detail::pass_through_container_container<
+ Container, ValueType, Attribute, Sequence
+ , typename traits::container_value<Attribute>::type>
+ {};
+
+ // Specialization for exposed optional attributes
+ //
+ // If the type embedded in the exposed optional is not a Fusion
+ // sequence we pass through the container attribute if it is compatible
+ // either to the optionals embedded type or to the containers value
+ // type.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence
+ , bool IsSequence = fusion::traits::is_sequence<Attribute>::value>
+ struct pass_through_container_optional
+ : mpl::or_<
+ traits::is_weak_substitute<Container, Attribute>
+ , traits::is_weak_substitute<ValueType, Attribute> >
+ {};
+
+ // If the embedded type of the exposed optional attribute is a Fusion
+ // sequence, we use the already existing logic for those.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container_optional<
+ Container, ValueType, Attribute, Sequence, true>
+ : pass_through_container_fusion_sequence<
+ Container, ValueType, Attribute, Sequence>
+ {};
+
+ ///////////////////////////////////////////////////////////////////////////
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container
+ : pass_through_container_base<Container, ValueType, Attribute, Sequence>
+ {};
+
+ // Handle optional attributes
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container<
+ Container, ValueType, boost::optional<Attribute>, Sequence>
+ : pass_through_container_optional<
+ Container, ValueType, Attribute, Sequence>
+ {};
+
+ // If both, the containers value type and the exposed attribute type are
+ // optionals we are allowed to pass through the container only if the
+ // embedded types of those optionals are not compatible.
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container<
+ Container, boost::optional<ValueType>, boost::optional<Attribute>
+ , Sequence>
+ : mpl::not_<traits::is_weak_substitute<ValueType, Attribute> >
+ {};
+
+ // Specialization for exposed variant attributes
+ //
+ // We pass through the container attribute if at least one of the embedded
+ // types in the variant requires to pass through the attribute
+
+#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
+ template <typename Container, typename ValueType, typename Sequence
+ , typename T>
+ struct pass_through_container<Container, ValueType, boost::variant<T>
+ , Sequence>
+ : pass_through_container<Container, ValueType, T, Sequence>
+ {};
+
+ template <typename Container, typename ValueType, typename Sequence
+ , typename T0, typename ...TN>
+ struct pass_through_container<Container, ValueType
+ , boost::variant<T0, TN...>, Sequence>
+ : mpl::bool_<pass_through_container<
+ Container, ValueType, T0, Sequence
+ >::type::value || pass_through_container<
+ Container, ValueType, boost::variant<TN...>, Sequence
+ >::type::value>
+ {};
+#else
+#define BOOST_SPIRIT_PASS_THROUGH_CONTAINER(z, N, _) \
+ pass_through_container<Container, ValueType, \
+ BOOST_PP_CAT(T, N), Sequence>::type::value || \
+ /***/
+
+ // make sure unused variant parameters do not affect the outcome
+ template <typename Container, typename ValueType, typename Sequence>
+ struct pass_through_container<Container, ValueType
+ , boost::detail::variant::void_, Sequence>
+ : mpl::false_
+ {};
+
+ template <typename Container, typename ValueType, typename Sequence
+ , BOOST_VARIANT_ENUM_PARAMS(typename T)>
+ struct pass_through_container<Container, ValueType
+ , boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Sequence>
+ : mpl::bool_<BOOST_PP_REPEAT(BOOST_VARIANT_LIMIT_TYPES
+ , BOOST_SPIRIT_PASS_THROUGH_CONTAINER, _) false>
+ {};
+
+#undef BOOST_SPIRIT_PASS_THROUGH_CONTAINER
+#endif
+}}}}
+
+///////////////////////////////////////////////////////////////////////////////
+namespace boost { namespace spirit { namespace traits
+{
+ ///////////////////////////////////////////////////////////////////////////
+ // forwarding customization point for domain karma::domain
+ template <typename Container, typename ValueType, typename Attribute
+ , typename Sequence>
+ struct pass_through_container<
+ Container, ValueType, Attribute, Sequence, karma::domain>
+ : karma::detail::pass_through_container<
+ Container, ValueType, Attribute, Sequence>
+ {};
+}}}
+
+namespace boost { namespace spirit { namespace karma { namespace detail
+{
+ template <typename Iterator>
+ struct pass_container_base
+ {
+ pass_container_base(Iterator begin, Iterator end)
+ : iter(begin), end(end)
+ {}
+
+ mutable Iterator iter;
+ mutable Iterator end;
+ };
+
+ template <typename Iterator>
+ struct pass_container_base<Iterator&>
+ {
+ pass_container_base(Iterator& begin, Iterator& end)
+ : iter(begin), end(end)
+ {}
+
+ Iterator& iter;
+ Iterator& end;
+ };
+
+ ///////////////////////////////////////////////////////////////////////////
+ // This function handles the case where the attribute (Attr) given
+ // to the sequence is an STL container. This is a wrapper around F.
+ // The function F does the actual generating.
+ template <typename F, typename Attr, typename Iterator, typename Sequence>
+ struct pass_container : pass_container_base<Iterator>
+ {
+ typedef pass_container_base<Iterator> base_type;
+ typedef typename F::context_type context_type;
+
+ pass_container(F const& f, Iterator begin, Iterator end)
+ : base_type(begin, end)
+ , f(f)
+ {}
+
+ bool is_at_end() const
+ {
+ return traits::compare(this->iter, this->end);
+ }
+
+ void next()
+ {
+ traits::next(this->iter);
+ }
+
+ // this is for the case when the current element expects an attribute
+ // which is taken from the next entry in the container
+ template <typename Component>
+ bool dispatch_container(Component const& component, mpl::false_) const
+ {
+ // get the next value to generate from container
+ if (!is_at_end() && !f(component, traits::deref(this->iter)))
+ {
+ // needs to return false as long as everything is ok
+ traits::next(this->iter);
+ return false;
+ }
+
+ // either no elements available any more or generation failed
+ return true;
+ }
+
+ // this is for the case when the current element is able to handle an
+ // attribute which is a container itself, this element will push its
+ // data directly into the attribute container
+ template <typename Component>
+ bool dispatch_container(Component const& component, mpl::true_) const
+ {
+ return f(component, make_iterator_range(this->iter, this->end));
+ }
+
+ ///////////////////////////////////////////////////////////////////////
+ // this is for the case when the current element doesn't expect an
+ // attribute
+ template <typename Component>
+ bool dispatch_attribute(Component const& component, mpl::false_) const
+ {
+ return f(component, unused);
+ }
+
+ // the current element expects an attribute
+ template <typename Component>
+ bool dispatch_attribute(Component const& component, mpl::true_) const
+ {
+ typedef typename traits::container_value<Attr>::type value_type;
+ typedef typename
+ traits::attribute_of<Component, context_type>::type
+ lhs_attribute;
+
+ // this predicate detects, whether the value type of the container
+ // attribute is a substitute for the attribute of the current
+ // element
+ typedef mpl::and_<
+ traits::handles_container<Component, Attr, context_type>
+ , traits::pass_through_container<
+ Attr, value_type, lhs_attribute, Sequence, karma::domain>
+ > predicate;
+
+ return dispatch_container(component, predicate());
+ }
+
+ // Dispatches to dispatch_main depending on the attribute type
+ // of the Component
+ template <typename Component>
+ bool operator()(Component const& component) const
+ {
+ // we need to dispatch depending on the type of the attribute
+ // of the current element (component). If this is has no attribute
+ // we shouldn't use an element of the container but unused_type
+ // instead
+ typedef traits::not_is_unused<
+ typename traits::attribute_of<Component, context_type>::type
+ > predicate;
+
+ return dispatch_attribute(component, predicate());
+ }
+
+ F f;
+
+ private:
+ // silence MSVC warning C4512: assignment operator could not be generated
+ pass_container& operator= (pass_container const&);
+ };
+}}}}
+
+#endif
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