From 99706347cd6d51e00f427a7985d3458402f9b905 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Wed, 25 Jan 2017 09:38:29 -0500
Subject: [PATCH] Make decorator copyable

---
 CHANGELOG.md                                  |  1 +
 include/beast/websocket/detail/decorator.hpp  | 62 +++++++++++++++++--
 .../beast/websocket/detail/stream_base.hpp    |  2 +-
 include/beast/websocket/impl/stream.ipp       |  6 +-
 4 files changed, 62 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b62cf34..b6d8be83 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 * bjam use clang on MACOSX
 * Simplify Travis package install specification
 * Add optional yield_to arguments
+* Make decorator copyable
 
 --------------------------------------------------------------------------------
 
diff --git a/include/beast/websocket/detail/decorator.hpp b/include/beast/websocket/detail/decorator.hpp
index 1250d35b..7d10587f 100644
--- a/include/beast/websocket/detail/decorator.hpp
+++ b/include/beast/websocket/detail/decorator.hpp
@@ -12,6 +12,7 @@
 #include <beast/http/message.hpp>
 #include <beast/http/string_body.hpp>
 #include <beast/version.hpp>
+#include <type_traits>
 #include <utility>
 
 namespace beast {
@@ -27,13 +28,17 @@ struct abstract_decorator
     virtual
     ~abstract_decorator() = default;
 
+    virtual
+    abstract_decorator*
+    copy() = 0;
+
     virtual
     void
     operator()(request_type& req) = 0;
 
     virtual
     void
-    operator()(response_type& resp) = 0;
+    operator()(response_type& res) = 0;
 };
 
 template<class T>
@@ -69,6 +74,7 @@ class decorator : public abstract_decorator
 
 public:
     decorator() = default;
+    decorator(decorator const&) = default;
 
     decorator(T&& t)
         : t_(std::move(t))
@@ -80,6 +86,12 @@ public:
     {
     }
 
+    abstract_decorator*
+    copy() override
+    {
+        return new decorator(*this);
+    }
+
     void
     operator()(request_type& req) override
     {
@@ -87,9 +99,9 @@ public:
     }
 
     void
-    operator()(response_type& resp) override
+    operator()(response_type& res) override
     {
-        (*this)(resp, typename call_res_possible::type{});
+        (*this)(res, typename call_res_possible::type{});
     }
 
 private:
@@ -124,8 +136,48 @@ struct default_decorator
 {
 };
 
-using decorator_type =
-    std::unique_ptr<abstract_decorator>;
+class decorator_type
+{
+    std::unique_ptr<abstract_decorator> p_;
+
+public:
+    decorator_type(decorator_type&&) = default;
+    decorator_type& operator=(decorator_type&&) = default;
+
+    decorator_type(decorator_type const& other)
+        : p_(other.p_->copy())
+    {
+    }
+
+    decorator_type&
+    operator=(decorator_type const& other)
+    {
+        p_ = std::unique_ptr<
+            abstract_decorator>{other.p_->copy()};
+        return *this;
+    }
+
+    template<class T, class =
+        typename std::enable_if<! std::is_same<
+            typename std::decay<T>::type,
+                decorator_type>::value>>
+    decorator_type(T&& t)
+        : p_(new decorator<T>{std::forward<T>(t)})
+    {
+    }
+
+    void
+    operator()(request_type& req)
+    {
+        (*p_)(req);
+    }
+
+    void
+    operator()(response_type& res)
+    {
+        (*p_)(res);
+    }
+};
 
 } // detail
 } // websocket
diff --git a/include/beast/websocket/detail/stream_base.hpp b/include/beast/websocket/detail/stream_base.hpp
index 2256d140..6bde6171 100644
--- a/include/beast/websocket/detail/stream_base.hpp
+++ b/include/beast/websocket/detail/stream_base.hpp
@@ -128,7 +128,7 @@ protected:
     stream_base& operator=(stream_base const&) = delete;
 
     stream_base()
-        : d_(new decorator<default_decorator>{})
+        : d_(detail::default_decorator{})
     {
     }
 
diff --git a/include/beast/websocket/impl/stream.ipp b/include/beast/websocket/impl/stream.ipp
index 2e419249..9d89f9cd 100644
--- a/include/beast/websocket/impl/stream.ipp
+++ b/include/beast/websocket/impl/stream.ipp
@@ -72,7 +72,7 @@ build_request(boost::string_ref const& host,
     key = detail::make_sec_ws_key(maskgen_);
     req.fields.insert("Sec-WebSocket-Key", key);
     req.fields.insert("Sec-WebSocket-Version", "13");
-    (*d_)(req);
+    d_(req);
     http::prepare(req, http::connection::upgrade);
     return req;
 }
@@ -91,7 +91,7 @@ build_response(http::request<Body, Fields> const& req)
             res.reason = http::reason_string(res.status);
             res.version = req.version;
             res.body = text;
-            (*d_)(res);
+            d_(res);
             prepare(res,
                 (is_keep_alive(req) && keep_alive_) ?
                     http::connection::keep_alive :
@@ -141,7 +141,7 @@ build_response(http::request<Body, Fields> const& req)
             detail::make_sec_ws_accept(key));
     }
     res.fields.replace("Server", "Beast.WSProto");
-    (*d_)(res);
+    d_(res);
     http::prepare(res, http::connection::upgrade);
     return res;
 }