1 files changed, 59 insertions, 0 deletions
diff --git a/include/crow/middleware_context.h b/include/crow/middleware_context.h
new file mode 100644
index 0000000..6885c13
--- /dev/null
+++ b/include/crow/middleware_context.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include "crow/utility.h"
+#include "crow/http_request.h"
+#include "crow/http_response.h"
+
+namespace crow
+{
+    namespace detail
+    {
+        template <typename ... Middlewares>
+        struct partial_context
+            : public black_magic::pop_back<Middlewares...>::template rebind<partial_context>
+            , public black_magic::last_element_type<Middlewares...>::type::context
+        {
+            using parent_context = typename black_magic::pop_back<Middlewares...>::template rebind<::crow::detail::partial_context>;
+            template <int N>
+            using partial = typename std::conditional<N == sizeof...(Middlewares)-1, partial_context, typename parent_context::template partial<N>>::type;
+
+            template <typename T> 
+            typename T::context& get()
+            {
+                return static_cast<typename T::context&>(*this);
+            }
+        };
+
+        template <>
+        struct partial_context<>
+        {
+            template <int>
+            using partial = partial_context;
+        };
+
+        template <int N, typename Context, typename Container, typename CurrentMW, typename ... Middlewares>
+        bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
+
+        template <typename ... Middlewares>
+        struct context : private partial_context<Middlewares...>
+        //struct context : private Middlewares::context... // simple but less type-safe
+        {
+            template <int N, typename Context, typename Container>
+            friend typename std::enable_if<(N==0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
+            template <int N, typename Context, typename Container>
+            friend typename std::enable_if<(N>0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
+
+            template <int N, typename Context, typename Container, typename CurrentMW, typename ... Middlewares2>
+            friend bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
+
+            template <typename T> 
+            typename T::context& get()
+            {
+                return static_cast<typename T::context&>(*this);
+            }
+
+            template <int N>
+            using partial = typename partial_context<Middlewares...>::template partial<N>;
+        };
+    }
+}