finish weak callback proxies

fluent++/CallbackContainer.h

@@ -20,19 +20,20 @@
 
 #include <unordered_map>
 
+#include <boost/any.hpp>
+#include <boost/optional.hpp>
+
 #include "Callback.h"
 
 class CallbackContainer
 {
     std::shared_ptr<CallbackContainer> self_reference;
 
+    typedef size_t handle_t;
+
     size_t handle;
 
-    struct InternalReference
+    std::unordered_map<decltype(handle), boost::any> container;
-    {
-    };
-
-    std::unordered_map<decltype(handle), InternalReference> container;
 
     template<typename _CTy, typename... Args>
     struct ProxyFactory;
@@ -40,14 +41,24 @@ class CallbackContainer
     template<typename _CTy, typename... Args>
     struct ProxyFactory<_CTy, std::tuple<Args...>>
     {
-        // Creates a weak callback proxy which prevents invoking to an invalid context.
+        // Creates a weak proxy callback which prevents invoking to an invalid context.
-        static callback_of_t<_CTy> CreateProxy(_CTy&& callback)
+        static callback_of_t<_CTy> CreateProxy(std::weak_ptr<CallbackContainer> const& weak_owner,
+            size_t const handle, weak_callback_of_t<_CTy> const& weak_callback)
         {
-            return [callback](Args&&... args)
+            return [=](Args&&... args)
+            {
+                // Try to get a pointer to the owner
+                if (auto const owner = weak_owner.lock())
+                    // And to the wrapped functional itself
+                    if (auto const callback = weak_callback.lock())
                     {
-
                         // Invoke the original callback
-                callback(std::forward<Args...>(args...));
+                        // FIXME: std::forward<Args..>(args...) causes errors when void
+                        (*callback)(args...);
+
+                        // Unregister the callback
+                        owner->InvalidateCallback(handle);
+                    }
             };
         }
     };
@@ -67,7 +78,6 @@ public:
     CallbackContainer& Clear()
     {
         container.clear();
-        handle = 0L;
         return *this;
     }
 
@@ -75,13 +85,32 @@ public:
     auto operator()(_CTy&& callback)
         -> callback_of_t<_CTy>
     {
+        // Create the shared callback
+        shared_callback_of_t<_CTy> shared_callback = make_shared_callback(std::forward<_CTy>(callback));
+
         // Create a weak proxy callback which removes the callback on execute
+        auto const this_handle = handle++;
         callback_of_t<_CTy> proxy =
             ProxyFactory<_CTy, ::fu::argument_type_of_t<_CTy>>::
-                CreateProxy(std::forward<_CTy>(callback));
+                CreateProxy(self_reference, this_handle, shared_callback);
 
+        container.insert(std::make_pair(this_handle, boost::any(std::move(shared_callback))));
         return std::move(proxy);
     }
+
+    boost::optional<handle_t> GetLastCallbackHandle() const
+    {
+        if (handle == 0L)
+            return boost::none;
+        else
+            return boost::make_optional(handle);
+    }
+
+    CallbackContainer& InvalidateCallback(handle_t const handle)
+    {
+        container.erase(handle);
+        return *this;
+    }
 };
 
 #endif /// _CALLBACK_CONTAINER_H_

test.cpp

@@ -4,6 +4,9 @@
 #include "Callback.h"
 #include "CallbackContainer.h"
 
+#include <iostream>
+#include <exception>
+
 void CastSpell(int id, Callback<bool> const& callback)
 {
     std::cout << "Cast " << id << std::endl;
@@ -47,12 +50,47 @@ int main(int argc, char** argv)
     
     });
 
+    Callback<> weak_cb_test;
+
+    {
         CallbackContainer callback;
 
-    auto mycb = callback([](bool success)
+        std::shared_ptr<int> dealloc_test(new int{2}, [](int* me)
         {
-
+            std::cout << "dealloc ok" << std::endl;
+            delete me;
         });
 
+        auto const cb_void = callback([dealloc_test]
+        {
+            std::cout << "huhu i'm a..." << std::endl;
+
+            auto const cp = dealloc_test;
+        });
+
+        dealloc_test.reset();
+
+        auto const cb_bool = callback([](bool success)
+        {
+            std::cout << "...weak wrapped callback!" << std::endl;
+        });
+
+        weak_cb_test = callback([]
+        {
+            std::cout << "huhu i'm crashsafe (you wont see me)!" << std::endl;
+            std::logic_error("bad logic");
+        });
+
+        cb_void();
+
+        int i = 0;
+        ++i;
+
+        cb_bool(true);
+    }
+
+    // This will never be executed because the CallbackContainer was deallocated and its weak callback proxies are crash safe.
+    weak_cb_test();
+
     return 0;
 }