Re: Avoiding the anonymous variable declaration RAII error...

From:

Greg Herlihy <greghe@mac.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Thu, 13 Mar 2008 11:59:33 CST

Message-ID:

<bd2ea86e-eac1-418a-820a-f2b60540b475@e6g2000prf.googlegroups.com>

On Mar 12, 6:37 pm, "Eric J. Holtman" <e...@ericholtman.com> wrote:

"Eric J. Holtman" <e...@ericholtman.com> wrote innews:Xns9A5E4E8002603ejhericholtmamcom@216.168.3.30:

However, it's a massive race condition just waiting to happen
if you forget the "lk", and just write:

void
process_threaded_data ()
{
Locker (m_mutex);

Well, it seems like the votes mostly go towards using
the pre-processor. I was hoping that there was some new
trick, either using templates, or hiding constructors,
that would work.

Actually there is a very simple technique to prevent an unnamed Locker
variable - just replace "Locker" in the variable's declaration with an
equivalent typedef:

     typedef Locker StLocker;

     void
     process_threaded_data ()
     {
          StLocker (m_mutex); // Error
          StLocker lk (m_mutex); // OK
          // ...

Greg

            .
            .
           .

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