Merge "libbinder: checked_interface_cast"

// ----------------------------------------------------------------------

/**

 * If this is a local object and the descriptor matches, this will return the

 * actual local object which is implementing the interface. Otherwise, this will

 * return a proxy to the interface without checking the interface descriptor.

 * This means that subsequent calls may fail with BAD_TYPE.

 */

template<typename INTERFACE>

inline sp<INTERFACE> interface_cast(const sp<IBinder>& obj)

{

    return INTERFACE::asInterface(obj);

}

/**

 * This is the same as interface_cast, except that it always checks to make sure

 * the descriptor matches, and if it doesn't match, it will return nullptr.

 */

template<typename INTERFACE>

inline sp<INTERFACE> checked_interface_cast(const sp<IBinder>& obj)

{

    if (obj->getInterfaceDescriptor() != INTERFACE::descriptor) {

        return nullptr;

    }

    return interface_cast<INTERFACE>(obj);

}

// ----------------------------------------------------------------------

template<typename INTERFACE>