Added any_adapter

Author: anarthal

include/boost/redis/any_adapter.hpp

@@ -0,0 +1,49 @@
+/* Copyright (c) 2018-2023 Marcelo Zimbres Silva ([email protected])
+ *
+ * Distributed under the Boost Software License, Version 1.0. (See
+ * accompanying file LICENSE.txt)
+ */
+
+#ifndef BOOST_REDIS_ANY_ADAPTER_HPP
+#define BOOST_REDIS_ANY_ADAPTER_HPP
+
+
+#include <boost/redis/resp3/node.hpp>
+#include <boost/redis/adapter/adapt.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <cstddef>
+#include <functional>
+#include <string_view>
+#include <type_traits>
+
+namespace boost::redis {
+
+class any_adapter
+{
+    using fn_type = std::function<void(std::size_t, resp3::basic_node<std::string_view> const&, system::error_code&)>;
+
+    struct impl_t {
+        fn_type adapt_fn;
+        std::size_t supported_response_size;
+    } impl_;
+
+    template <class T>
+    static auto create_impl(T& response) -> impl_t
+    {
+        using namespace boost::redis::adapter;
+        auto adapter = boost_redis_adapt(response);
+        std::size_t size = adapter.get_supported_response_size();
+        return { std::move(adapter), size };
+    }
+
+public:
+    template <class T, class = std::enable_if_t<!std::is_same_v<T, any_adapter>>>
+    explicit any_adapter(T& response) : impl_(create_impl(response)) {}
+
+    // TODO: make this private
+    auto get_impl() && { return std::move(impl_); }
+};
+
+}
+
+#endif

include/boost/redis/connection.hpp

@@ -7,6 +7,7 @@
 #ifndef BOOST_REDIS_CONNECTION_HPP
 #define BOOST_REDIS_CONNECTION_HPP
 
+#include <boost/redis/any_adapter.hpp>
 #include <boost/redis/detail/connection_base.hpp>
 #include <boost/redis/logger.hpp>
 #include <boost/redis/config.hpp>
@@ -256,7 +257,18 @@ class basic_connection {
       Response& resp = ignore,
       CompletionToken&& token = CompletionToken{})
    {
-      return impl_.async_exec(req, resp, std::forward<CompletionToken>(token));
+      return impl_.async_exec(req, any_adapter(resp), std::forward<CompletionToken>(token));
+   }
+
+
+   template <class CompletionToken = asio::default_completion_token_t<executor_type>>
+   auto
+   async_exec(
+      request const& req,
+      any_adapter adapter,
+      CompletionToken&& token = CompletionToken{})
+   {
+      return impl_.async_exec(req, std::move(adapter), std::forward<CompletionToken>(token));
    }
 
    /** @brief Cancel operations.
@@ -394,7 +406,13 @@ class connection {
    template <class Response, class CompletionToken>
    auto async_exec(request const& req, Response& resp, CompletionToken token)
    {
-      return impl_.async_exec(req, resp, std::move(token));
+      return async_exec(req, any_adapter(resp), std::move(token));
+   }
+
+   template <class CompletionToken>
+   auto async_exec(request const& req, any_adapter adapter, CompletionToken token)
+   {
+      return impl_.async_exec(req, std::move(adapter), std::move(token));
    }
 
    /// Calls `boost::redis::basic_connection::cancel`.

include/boost/redis/detail/connection_base.hpp

@@ -7,6 +7,7 @@
 #ifndef BOOST_REDIS_CONNECTION_BASE_HPP
 #define BOOST_REDIS_CONNECTION_BASE_HPP
 
+#include <boost/redis/any_adapter.hpp>
 #include <boost/redis/adapter/adapt.hpp>
 #include <boost/redis/detail/helper.hpp>
 #include <boost/redis/error.hpp>
@@ -39,6 +40,7 @@
 #include <string_view>
 #include <type_traits>
 #include <functional>
+#include <utility>
 
 namespace boost::redis::detail
 {
@@ -440,21 +442,26 @@ class connection_base {
       cancel_impl(op);
    }
 
-   template <class Response, class CompletionToken>
-   auto async_exec(request const& req, Response& resp, CompletionToken token)
+   template <class CompletionToken>
+   auto async_exec(request const& req, any_adapter adapter, CompletionToken token)
    {
-      using namespace boost::redis::adapter;
-      auto f = boost_redis_adapt(resp);
-      BOOST_ASSERT_MSG(req.get_expected_responses() <= f.get_supported_response_size(), "Request and response have incompatible sizes.");
+      auto adapter_impl = std::move(adapter).get_impl();
+      BOOST_ASSERT_MSG(req.get_expected_responses() <= adapter_impl.supported_response_size, "Request and response have incompatible sizes.");
 
-      auto info = std::make_shared<req_info>(req, f, get_executor());
+      auto info = std::make_shared<req_info>(req, std::move(adapter_impl.adapt_fn), get_executor());
 
       return asio::async_compose
          < CompletionToken
          , void(system::error_code, std::size_t)
          >(exec_op<this_type>{this, info}, token, writer_timer_);
    }
 
+   template <class Response, class CompletionToken>
+   auto async_exec(request const& req, Response& resp, CompletionToken token)
+   {
+      return async_exec(req, any_adapter(resp), std::forward<CompletionToken>(token));
+   }
+
    template <class Response, class CompletionToken>
    [[deprecated("Set the response with set_receive_response and use the other overload.")]]
    auto async_receive(Response& response, CompletionToken token)