1 files changed, 63 insertions, 0 deletions
diff --git a/mojo/public/cpp/bindings/lib/shared_ptr.h b/mojo/public/cpp/bindings/lib/shared_ptr.h
new file mode 100644
index 0000000..6ae53a5
--- /dev/null
+++ b/mojo/public/cpp/bindings/lib/shared_ptr.h
@@ -0,0 +1,63 @@
+// Copyright 2014 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.
+
+#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_
+
+#include "mojo/public/cpp/bindings/lib/shared_data.h"
+
+namespace mojo {
+namespace internal {
+
+// Used to manage a heap-allocated instance of P that can be shared via
+// reference counting. When the last reference is dropped, the instance is
+// deleted.
+template <typename P>
+class SharedPtr {
+ public:
+  SharedPtr() {}
+
+  explicit SharedPtr(P* ptr) {
+    impl_.mutable_value()->ptr = ptr;
+  }
+
+  // Default copy-constructor and assignment operator are OK.
+
+  P* get() {
+    return impl_.value().ptr;
+  }
+  const P* get() const {
+    return impl_.value().ptr;
+  }
+
+  P* operator->() { return get(); }
+  const P* operator->() const { return get(); }
+
+ private:
+  class Impl {
+   public:
+    ~Impl() {
+      if (ptr)
+        delete ptr;
+    }
+
+    Impl() : ptr(NULL) {
+    }
+
+    Impl(P* ptr) : ptr(ptr) {
+    }
+
+    P* ptr;
+
+   private:
+    MOJO_DISALLOW_COPY_AND_ASSIGN(Impl);
+  };
+
+  SharedData<Impl> impl_;
+};
+
+}  // namespace mojo
+}  // namespace internal
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_