Function-type templated CallbackRegistry

base/callback_registry.h

Index: base/callback_registry.h
diff --git a/base/callback_registry.h b/base/callback_registry.h
index fcacbf549f2a79412130e0b1d902715a9663cca0..8218448e8f814506b2417ea17a3d672332a2dc63 100644
--- a/base/callback_registry.h
+++ b/base/callback_registry.h
@@ -1,3 +1,8 @@
+// This file was GENERATED by command:
+//     pump.py callback_registry.h.pump
+// DO NOT EDIT BY HAND!!!
+
+
 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
@@ -173,44 +178,213 @@ class CallbackRegistryBase {
 
 }  // namespace internal
 
-template <typename Details>
-class CallbackRegistry
-    : public internal::CallbackRegistryBase<Callback<void(const Details&)> > {
+template <typename Sig> class CallbackRegistry;
+template <>
+class CallbackRegistry<void(void)>
+    : public internal::CallbackRegistryBase<Callback<void(void)> > {
  public:
+  typedef Callback<void(void)> CallbackType;
+
   CallbackRegistry() {}
 
-  // Execute all active callbacks with |details| parameter.
-  void Notify(const Details& details) {
-    typename internal::CallbackRegistryBase<
-        Callback<void(const Details&)> >::Iterator it = this->GetIterator();
-    Callback<void(const Details&)>* cb;
+  void Notify() {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
     while((cb = it.GetNext()) != NULL) {
-      cb->Run(details);
+      cb->Run();
     }
   }
 
-private:
+ private:
   DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+

[erikwright (departed), 2013/09/13 15:05:56]

remove blanks

[Cait (Slow), 2013/09/13 19:07:58]

Done.

+
 };
 
-template <> class CallbackRegistry<void>
-    : public internal::CallbackRegistryBase<Closure> {
+template <typename A1>
+class CallbackRegistry<void(const A1&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&)> > {
  public:
+  typedef Callback<void(const A1&)> CallbackType;
+
   CallbackRegistry() {}
 
-  // Execute all active callbacks.
-  void Notify() {
-    Iterator it = this->GetIterator();
-    Closure* cb;
+  void Notify(const A1& a1) {

[awong, 2013/09/12 21:17:47]

BTW, forgot to mention...we should explicitly specify behavior for move-only
types (eg scoped_ptr), array types, and other such fun.  Look at
CallbackParamTraits::ForwardType to see the domain of problems that can come up:
 
https://code.google.com/p/chromium/codesearch#chromium/src/base/callback_inte...

Move-only types almost certainly should be disallowed since the behavior is
non-sensical in the context of multiple callbacks.

[erikwright (departed), 2013/09/13 15:05:56]

What's the danger here? It will fail to compile, and correctly so, for movable
types, right? Line 219 would not find a viable constructor if A1 is scoped_ptr
(assuming that we move the forced const&).

[Cait (Slow), 2013/09/13 19:07:58]

So will I need to create something similar to CallbackParameterTraits then to
ensure that params of different types (refs, ptrs etc), are handled properly
(but w/o moveable types support)?

+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
     while((cb = it.GetNext()) != NULL) {
-      cb->Run();
+      cb->Run(a1);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2>
+class CallbackRegistry<void(const A1&, const A2&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2);
     }
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2, typename A3>
+class CallbackRegistry<void(const A1&, const A2&, const A3&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&, const A3&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&, const A3&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2, const A3& a3) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2, typename A3, typename A4>
+class CallbackRegistry<void(const A1&, const A2&, const A3&, const A4&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&, const A3&, const A4&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&, const A3&,
+      const A4&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2, const A3& a3, const A4& a4) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5>
+class CallbackRegistry<void(const A1&, const A2&, const A3&, const A4&,
+    const A5&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&, const A3&, const A4&,
+              const A5&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&, const A3&, const A4&,
+      const A5&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2, const A3& a3, const A4& a4,
+      const A5& a5) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5,
+    typename A6>
+class CallbackRegistry<void(const A1&, const A2&, const A3&, const A4&,
+    const A5&, const A6&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&, const A3&, const A4&, const A5&,
+              const A6&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&, const A3&, const A4&, const A5&,
+      const A6&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2, const A3& a3, const A4& a4,
+      const A5& a5, const A6& a6) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5, a6);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5,
+    typename A6, typename A7>
+class CallbackRegistry<void(const A1&, const A2&, const A3&, const A4&,
+    const A5&, const A6&, const A7&)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(const A1&, const A2&, const A3&, const A4&, const A5&,
+              const A6&, const A7&)> > {
+ public:
+  typedef Callback<void(const A1&, const A2&, const A3&, const A4&, const A5&,
+      const A6&, const A7&)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(const A1& a1, const A2& a2, const A3& a3, const A4& a4,
+      const A5& a5, const A6& a6, const A7& a7) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5, a6, a7);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+
+
 };
 
 }  // namespace base
 
-#endif  // BASE_CALLBACK_REGISTRY_H_
+#endif  // BASE_CALLBACK_REGISTRY_H