code pattern for locking & unlocking

Hi!

I often have to acquire locks and release them after I'm finished with
them.
I use constructor/destructor to acquire & release locks. everything
works fine.
sometime I must acquire a lock for few instructions, then release it
in the middle of a big function. I use braces to get timely
destructors, but I find the "middle of nowhere" braces kind of
embarrassing.
something like:

struct Lock
{
Lock(Mutex& mtx) mtx_(mtx) { mtx.lock(); }
~Lock() { mtx_.unlock(); }
operator bool() { return true;}
};

void someFunc()
{
  // do some stuff
  ...
  // now time to update share data
  {
     Lock myLock(data_mutex);
     //use locked data
     ....
  } // destructor called
  // do more stuff
  ...
}

I would like to have something like the using keyword in c#.
Is there a way to fake it in C++ ?
for now I'm using an if to do it.

void someFunc()
{
  // do some stuff
  ...
  // now time to update share data
  if (Lock myLock = Lock(data_mutex))
  {
     //use locked data
     ....
  } // Unlock done by destructor

  // do more stuff
  ...
}

Is it good programming ?
Is there a better way ?

Thanks

Daniel Anderson

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