Added boost header

test/external/boost/proto/transform/detail/when.hpp

@@ -0,0 +1,109 @@
+#if !defined(BOOST_PROTO_DONT_USE_PREPROCESSED_FILES)
+
+    #include <boost/proto/transform/detail/preprocessed/when.hpp>
+
+#elif !defined(BOOST_PP_IS_ITERATING)
+
+    #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES)
+        #pragma wave option(preserve: 2, line: 0, output: "preprocessed/when.hpp")
+    #endif
+
+    ///////////////////////////////////////////////////////////////////////////////
+    /// \file when.hpp
+    /// Definition of when transform.
+    //
+    //  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)
+
+    #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES)
+        #pragma wave option(preserve: 1)
+    #endif
+
+    #define BOOST_PP_ITERATION_PARAMS_1                                                             \
+        (3, (0, BOOST_PROTO_MAX_ARITY, <boost/proto/transform/detail/when.hpp>))
+    #include BOOST_PP_ITERATE()
+
+    #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES)
+        #pragma wave option(output: null)
+    #endif
+
+#else
+
+    #define N BOOST_PP_ITERATION()
+
+    /// \brief A grammar element and a PrimitiveTransform that associates
+    /// a transform with the grammar.
+    ///
+    /// Use <tt>when\<\></tt> to override a grammar's default transform
+    /// with a custom transform. It is for used when composing larger
+    /// transforms by associating smaller transforms with individual
+    /// rules in your grammar, as in the following transform which
+    /// counts the number of terminals in an expression.
+    ///
+    /// \code
+    /// // Count the terminals in an expression tree.
+    /// // Must be invoked with initial state == mpl::int_<0>().
+    /// struct CountLeaves
+    ///   : or_<
+    ///         when<terminal<_>, mpl::next<_state>()>
+    ///       , otherwise<fold<_, _state, CountLeaves> >
+    ///     >
+    /// {};
+    /// \endcode
+    ///
+    /// The <tt>when\<G, R(A0,A1,...)\></tt> form accepts either a
+    /// CallableTransform or an ObjectTransform as its second parameter.
+    /// <tt>when\<\></tt> uses <tt>is_callable\<R\>::value</tt> to
+    /// distinguish between the two, and uses <tt>call\<\></tt> to
+    /// evaluate CallableTransforms and <tt>make\<\></tt> to evaluate
+    /// ObjectTransforms.
+    template<typename Grammar, typename R BOOST_PP_ENUM_TRAILING_PARAMS(N, typename A)>
+    struct when<Grammar, R(BOOST_PP_ENUM_PARAMS(N, A))>
+      : transform<when<Grammar, R(BOOST_PP_ENUM_PARAMS(N, A))> >
+    {
+        typedef Grammar first;
+        typedef R second(BOOST_PP_ENUM_PARAMS(N, A));
+        typedef typename Grammar::proto_grammar proto_grammar;
+
+        // Note: do not evaluate is_callable<R> in this scope.
+        // R may be an incomplete type at this point.
+
+        template<typename Expr, typename State, typename Data>
+        struct impl : transform_impl<Expr, State, Data>
+        {
+            // OK to evaluate is_callable<R> here. R should be compete by now.
+            typedef
+                typename mpl::if_c<
+                    is_callable<R>::value
+                  , call<R(BOOST_PP_ENUM_PARAMS(N, A))> // "R" is a function to call
+                  , make<R(BOOST_PP_ENUM_PARAMS(N, A))> // "R" is an object to construct
+                >::type
+            which;
+
+            typedef typename which::template impl<Expr, State, Data>::result_type result_type;
+
+            /// Evaluate <tt>R(A0,A1,...)</tt> as a transform either with
+            /// <tt>call\<\></tt> or with <tt>make\<\></tt> depending on
+            /// whether <tt>is_callable\<R\>::value</tt> is \c true or
+            /// \c false.
+            ///
+            /// \param e The current expression
+            /// \param s The current state
+            /// \param d An arbitrary data
+            /// \pre <tt>matches\<Expr, Grammar\>::value</tt> is \c true
+            /// \return <tt>which()(e, s, d)</tt>
+            result_type operator ()(
+                typename impl::expr_param   e
+              , typename impl::state_param  s
+              , typename impl::data_param   d
+            ) const
+            {
+                return typename which::template impl<Expr, State, Data>()(e, s, d);
+            }
+        };
+    };
+
+    #undef N
+
+#endif