comparison DEPENDENCIES/generic/include/boost/spirit/home/qi/detail/pass_container.hpp @ 16:2665513ce2d3

Add boost headers

+/*=============================================================================
+    Copyright (c) 2001-2011 Joel de Guzman
+    Copyright (c) 2001-2011 Hartmut Kaiser
+
+    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_JANUARY_06_2009_0802PM)
+#define SPIRIT_PASS_CONTAINER_JANUARY_06_2009_0802PM
+
+#if defined(_MSC_VER)
+#pragma once
+#endif
+
+#include <boost/spirit/home/qi/detail/attributes.hpp>
+#include <boost/spirit/home/support/container.hpp>
+#include <boost/spirit/home/support/handles_container.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>
+
+namespace boost { namespace spirit { namespace qi { 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, Attribute, ValueType>
+    {};
+
+    // 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, Attribute, Container>
+          , negate_weak_substitute_if_not<Sequence, Attribute, ValueType> >
+    {};
+
+    // 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<Attribute, Container> 
+          , traits::is_weak_substitute<AttributeValueType, Container> >
+    {};
+
+    // 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<Attribute, Container> 
+          , traits::is_weak_substitute<Attribute, ValueType> >
+    {};
+
+    // 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 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<Attribute, ValueType> > 
+    {};
+
+    // 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
+
+#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
+}}}}
+
+///////////////////////////////////////////////////////////////////////////////
+namespace boost { namespace spirit { namespace traits
+{
+    ///////////////////////////////////////////////////////////////////////////
+    // forwarding customization point for domain qi::domain
+    template <typename Container, typename ValueType, typename Attribute
+      , typename Sequence>
+    struct pass_through_container<
+            Container, ValueType, Attribute, Sequence, qi::domain>
+      : qi::detail::pass_through_container<
+            Container, ValueType, Attribute, Sequence>
+    {};
+}}}
+
+namespace boost { namespace spirit { namespace qi { namespace detail
+{
+    ///////////////////////////////////////////////////////////////////////////
+    // This function handles the case where the attribute (Attr) given
+    // the sequence is an STL container. This is a wrapper around F.
+    // The function F does the actual parsing.
+    template <typename F, typename Attr, typename Sequence>
+    struct pass_container
+    {
+        typedef typename F::context_type context_type;
+        typedef typename F::iterator_type iterator_type;
+
+        pass_container(F const& f_, Attr& attr_)
+          : f(f_), attr(attr_) {}
+
+        // this is for the case when the current element exposes an attribute
+        // which is pushed back onto the container
+        template <typename Component>
+        bool dispatch_container(Component const& component, mpl::false_) const
+        {
+            // synthesized attribute needs to be default constructed
+            typename traits::container_value<Attr>::type val =
+                typename traits::container_value<Attr>::type();
+
+            iterator_type save = f.first;
+            bool r = f(component, val);
+            if (!r)
+            {
+                // push the parsed value into our attribute
+                r = !traits::push_back(attr, val);
+                if (r)
+                    f.first = save;
+            }
+            return r;
+        }
+
+        // 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, attr);
+        }
+
+        ///////////////////////////////////////////////////////////////////////
+        // 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, iterator_type>::type
+            rhs_attribute;
+
+            // this predicate detects, whether the attribute of the current 
+            // element is a substitute for the value type of the container
+            // attribute 
+            typedef mpl::and_<
+                traits::handles_container<
+                    Component, Attr, context_type, iterator_type> 
+              , traits::pass_through_container<
+                    Attr, value_type, rhs_attribute, Sequence, qi::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 pass an attribute at all.
+            typedef typename traits::not_is_unused<
+                typename traits::attribute_of<
+                    Component, context_type, iterator_type
+                >::type
+            >::type predicate;
+
+            // ensure the attribute is actually a container type
+            traits::make_container(attr);
+
+            return dispatch_attribute(component, predicate());
+        }
+
+        F f;
+        Attr& attr;
+
+    private:
+        // silence MSVC warning C4512: assignment operator could not be generated
+        pass_container& operator= (pass_container const&);
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    // Utility function to make a pass_container for container components 
+    // (kleene, list, plus, repeat)
+    template <typename F, typename Attr>
+    inline pass_container<F, Attr, mpl::false_>
+    make_pass_container(F const& f, Attr& attr)
+    {
+        return pass_container<F, Attr, mpl::false_>(f, attr);
+    }
+
+    // Utility function to make a pass_container for sequences
+    template <typename F, typename Attr>
+    inline pass_container<F, Attr, mpl::true_>
+    make_sequence_pass_container(F const& f, Attr& attr)
+    {
+        return pass_container<F, Attr, mpl::true_>(f, attr);
+    }
+}}}}
+
+#endif
+