Added boost header

test/external/boost/proto/eval.hpp

@@ -0,0 +1,140 @@
+///////////////////////////////////////////////////////////////////////////////
+/// \file eval.hpp
+/// Contains the eval() expression evaluator.
+//
+//  Copyright 2008 Eric Niebler. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_PROTO_EVAL_HPP_EAN_03_29_2007
+#define BOOST_PROTO_EVAL_HPP_EAN_03_29_2007
+
+#include <boost/proto/proto_fwd.hpp> // BOOST_PROTO_CALLABLE
+#include <boost/type_traits/remove_reference.hpp>
+
+namespace boost { namespace proto
+{
+
+    namespace result_of
+    {
+        /// \brief A metafunction for calculating the return type
+        /// of \c proto::eval() given a certain \c Expr and \c Context
+        /// types.
+        ///
+        /// \note The types \c Expr and \c Context should not be
+        /// reference types. They may be cv-qualified, but the
+        /// cv-qualification on the \c Context parameter is ignored.
+        template<typename Expr, typename Context>
+        struct eval
+        {
+            typedef typename Context::template eval<Expr>::result_type type;
+        };
+    }
+
+    namespace functional
+    {
+        /// \brief A PolymorphicFunctionObject type for
+        /// evaluating a given Proto expression with a given
+        /// context.
+        struct eval
+        {
+            BOOST_PROTO_CALLABLE()
+
+            template<typename Sig>
+            struct result;
+
+            template<typename This, typename Expr, typename Context>
+            struct result<This(Expr, Context)>
+            {
+                typedef
+                    typename proto::result_of::eval<
+                        typename remove_reference<Expr>::type
+                      , typename remove_reference<Context>::type
+                    >::type
+                type;
+            };
+
+            /// \brief Evaluate a given Proto expression with a given
+            /// context.
+            /// \param expr The Proto expression to evaluate
+            /// \param context The context in which the expression should be
+            ///     evaluated.
+            /// \return <tt>typename Context::template eval<Expr>()(expr, context)</tt>
+            template<typename Expr, typename Context>
+            typename proto::result_of::eval<Expr, Context>::type
+            operator ()(Expr &e, Context &ctx) const
+            {
+                return typename Context::template eval<Expr>()(e, ctx);
+            }
+
+            /// \overload
+            ///
+            template<typename Expr, typename Context>
+            typename proto::result_of::eval<Expr, Context>::type
+            operator ()(Expr &e, Context const &ctx) const
+            {
+                return typename Context::template eval<Expr>()(e, ctx);
+            }
+
+            /// \overload
+            ///
+            template<typename Expr, typename Context>
+            typename proto::result_of::eval<Expr const, Context>::type
+            operator ()(Expr const &e, Context &ctx) const
+            {
+                return typename Context::template eval<Expr const>()(e, ctx);
+            }
+
+            /// \overload
+            ///
+            template<typename Expr, typename Context>
+            typename proto::result_of::eval<Expr const, Context>::type
+            operator ()(Expr const &e, Context const &ctx) const
+            {
+                return typename Context::template eval<Expr const>()(e, ctx);
+            }
+        };
+    }
+
+    /// \brief Evaluate a given Proto expression with a given
+    /// context.
+    /// \param expr The Proto expression to evaluate
+    /// \param context The context in which the expression should be
+    ///     evaluated.
+    /// \return <tt>typename Context::template eval<Expr>()(expr, context)</tt>
+    template<typename Expr, typename Context>
+    typename proto::result_of::eval<Expr, Context>::type
+    eval(Expr &e, Context &ctx)
+    {
+        return typename Context::template eval<Expr>()(e, ctx);
+    }
+
+    /// \overload
+    ///
+    template<typename Expr, typename Context>
+    typename proto::result_of::eval<Expr, Context>::type
+    eval(Expr &e, Context const &ctx)
+    {
+        return typename Context::template eval<Expr>()(e, ctx);
+    }
+
+    /// \overload
+    ///
+    template<typename Expr, typename Context>
+    typename proto::result_of::eval<Expr const, Context>::type
+    eval(Expr const &e, Context &ctx)
+    {
+        return typename Context::template eval<Expr const>()(e, ctx);
+    }
+
+    /// \overload
+    ///
+    template<typename Expr, typename Context>
+    typename proto::result_of::eval<Expr const, Context>::type
+    eval(Expr const &e, Context const &ctx)
+    {
+        return typename Context::template eval<Expr const>()(e, ctx);
+    }
+}}
+
+#endif