include/middleware_context.h


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

#pragma once

#include "utility.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
        {
        };

        template <>
        struct partial_context<>
        {
        };

        template <typename ... Middlewares>
        struct context : private partial_context<Middlewares...>
        //struct context : private Middlewares::context... // simple but less type-safe
        {
            template <typename T> 
            typename T::context& get()
            {
                return static_cast<typename T::context&>(*this);
            }
        };
    }
}