1 files changed, 150 insertions, 0 deletions
diff --git a/boost/spirit/home/x3/support/traits/print_attribute.hpp b/boost/spirit/home/x3/support/traits/print_attribute.hpp
new file mode 100644
index 0000000000..47bffce1a1
--- /dev/null
+++ b/boost/spirit/home/x3/support/traits/print_attribute.hpp
@@ -0,0 +1,150 @@
+/*=============================================================================
+    Copyright (c) 2001-2014 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(BOOST_SPIRIT_X3_PRINT_ATTRIBUTE_JANUARY_20_2013_0814AM)
+#define BOOST_SPIRIT_X3_PRINT_ATTRIBUTE_JANUARY_20_2013_0814AM
+
+#if defined(_MSC_VER)
+#pragma once
+#endif
+
+#include <boost/variant.hpp>
+#include <boost/optional/optional.hpp>
+#include <boost/fusion/include/is_sequence.hpp>
+#include <boost/fusion/include/for_each.hpp>
+#include <boost/spirit/home/x3/support/traits/attribute_category.hpp>
+#include <boost/spirit/home/x3/support/traits/is_variant.hpp>
+
+namespace boost { namespace spirit { namespace x3 { namespace traits
+{
+    template <typename Out, typename T>
+    void print_attribute(Out& out, T const& val);
+
+    template <typename Out>
+    inline void print_attribute(Out&, unused_type) {}
+
+    ///////////////////////////////////////////////////////////////////////////
+    namespace detail
+    {
+        template <typename Out>
+        struct print_fusion_sequence
+        {
+            print_fusion_sequence(Out& out)
+              : out(out), is_first(true) {}
+
+            typedef void result_type;
+
+            template <typename T>
+            void operator()(T const& val) const
+            {
+                if (is_first)
+                    is_first = false;
+                else
+                    out << ", ";
+                x3::traits::print_attribute(out, val);
+            }
+
+            Out& out;
+            mutable bool is_first;
+        };
+
+        // print elements in a variant
+        template <typename Out>
+        struct print_visitor : static_visitor<>
+        {
+            print_visitor(Out& out) : out(out) {}
+
+            template <typename T>
+            void operator()(T const& val) const
+            {
+                x3::traits::print_attribute(out, val);
+            }
+
+            Out& out;
+        };
+    }
+
+    template <typename Out, typename T, typename Enable = void>
+    struct print_attribute_debug
+    {
+        // for plain data types
+        template <typename T_>
+        static void call(Out& out, T_ const& val, unused_attribute)
+        {
+            out << "unused";
+        }
+
+        // for plain data types
+        template <typename T_>
+        static void call(Out& out, T_ const& val, plain_attribute)
+        {
+            out << val;
+        }
+
+        // for fusion data types
+        template <typename T_>
+        static void call(Out& out, T_ const& val, tuple_attribute)
+        {
+            out << '[';
+            fusion::for_each(val, detail::print_fusion_sequence<Out>(out));
+            out << ']';
+        }
+
+        // stl container
+        template <typename T_>
+        static void call(Out& out, T_ const& val, container_attribute)
+        {
+            out << '[';
+            if (!traits::is_empty(val))
+            {
+                bool first = true;
+                typename container_iterator<T_ const>::type iend = traits::end(val);
+                for (typename container_iterator<T_ const>::type i = traits::begin(val);
+                     !traits::compare(i, iend); traits::next(i))
+                {
+                    if (!first)
+                        out << ", ";
+                    first = false;
+                    x3::traits::print_attribute(out, traits::deref(i));
+                }
+            }
+            out << ']';
+        }
+
+        // for variant types
+        template <typename T_>
+        static void call(Out& out, T_ const& val, variant_attribute)
+        {
+            apply_visitor(detail::print_visitor<Out>(out), val);
+        }
+
+        // for optional types
+        template <typename T_>
+        static void call(Out& out, T_ const& val, optional_attribute)
+        {
+            if (val)
+                x3::traits::print_attribute(out, *val);
+            else
+                out << "[empty]";
+        }
+
+        // main entry point
+        static void call(Out& out, T const& val)
+        {
+            call(out, val, typename attribute_category<T>::type());
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename Out, typename T>
+    inline void print_attribute(Out& out, T const& val)
+    {
+        print_attribute_debug<Out, T>::call(out, val);
+    }
+}}}}
+
+#endif