c++ - What is the purpose of the statement "(void)c;"?

Question

Sorry for the vague title, but not really sure how to phrase it. So I was looking through the innards of boost::asio (trying to track down some ridiculous delays), and I notice code like this dotted about:

    op_queue<operation> completed_ops;
    task_cleanup c = { this, &lock, &completed_ops };
    (void)c;  // EH?

Now from the name of the struct that is being initialized, I'm guessing it's using RAII to do some steps on destruction - fine, but what is the purpose of the last line? Have I just missed something completely funky?

Answer 1

Maybe to avoid a compilation warning because c isn't used?