Declient calculator test mojom.

mojo/public/cpp/bindings/callback.h

Index: mojo/public/cpp/bindings/callback.h
diff --git a/mojo/public/cpp/bindings/callback.h b/mojo/public/cpp/bindings/callback.h
index d7bab1632fb87397c817123e4bdbe2e9a263a2de..1c30e401b9373dabead7f9177d2cc5688056159f 100644
--- a/mojo/public/cpp/bindings/callback.h
+++ b/mojo/public/cpp/bindings/callback.h
@@ -62,6 +62,32 @@ class Callback<void(Args...)> {
 
 typedef Callback<void()> Closure;
 
+namespace {

[jamesr, 2015/01/22 22:45:24]

anonymous namespace inside a header is almost never what you want - it means
that if two translation units #include this header they will not have a shared
type that they can refer to

[Aaron Boodman, 2015/01/22 22:49:08]

You're right, thanks.

+
+template <typename Method, typename Class>
+class RunnableImpl {

[jamesr, 2015/01/22 22:45:24]

don't put this in public. If you want it in your test feel free to put it there,
but I think if we're going to expand the public Callback we should have it
actually accept real functors for Sink.  The c++11 patch I linked earlier does
this and it's possible to do so in c++98 with SFINAE but nobody's got around to
doing that.  This adds another confusing layer without letting you use the
syntax you really want.

[Aaron Boodman, 2015/01/22 22:49:08]

done.

+ public:
+  RunnableImpl(Method method, Class instance)
+      : method_(method), instance_(instance) {}
+  template <typename... Args>
+  void Run(Args... args) const {
+    (instance_->*method_)(args...);
+  }
+
+ private:
+  Method method_;
+  Class instance_;
+};
+
+}  // namespace
+
+// Convenience to create a create a runnable for any method.
+// |Class| can be any copyable type with an -> operator.
+template <typename Method, typename Class>
+RunnableImpl<Method, Class> MakeRunnable(Method method, Class object) {
+  return RunnableImpl<Method, Class>(method, object);
+}
+
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_CALLBACK_H_