1 files changed, 41 insertions, 0 deletions
diff --git a/ppapi/cpp/module_impl.h b/ppapi/cpp/module_impl.h
new file mode 100644
index 0000000..9cde170
--- /dev/null
+++ b/ppapi/cpp/module_impl.h
@@ -0,0 +1,41 @@
+// Copyright (c) 2010 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 PPAPI_CPP_MODULE_IMPL_H_
+#define PPAPI_CPP_MODULE_IMPL_H_
+
+#include "ppapi/cpp/module.h"
+
+namespace {
+
+template <typename T> class DeviceFuncs {
+ public:
+  explicit DeviceFuncs(const char* ifname) : ifname_(ifname), funcs_(NULL) {}
+
+  operator T const*() {
+    if (!funcs_) {
+      funcs_ = reinterpret_cast<T const*>(
+          pp::Module::Get()->GetBrowserInterface(ifname_));
+    }
+    return funcs_;
+  }
+
+  // This version doesn't check for existence of the function object. It is
+  // used so that, for DeviceFuncs f, the expression:
+  // if (f) f->doSomething();
+  // checks the existence only once.
+  T const* operator->() const { return funcs_; }
+
+ private:
+  DeviceFuncs(const DeviceFuncs&other);
+  DeviceFuncs &operator=(const DeviceFuncs &other);
+
+  const char* ifname_;
+  T const* funcs_;
+};
+
+}  // namespace
+
+#endif  // PPAPI_CPP_MODULE_IMPL_H_
+