Re: How to avoid unreferenced objects (mutexes etc)

[Hyman Rosen <hyrosen@mail.com>]

Matthew Heaney wrote:

> The problem is that the language doesn't have a termination handler for
> blocks, a la a "finally" clause in Java or Win32 Structured Exception
> Handling.  So you have to create "unused" objects as a work-around.


In C++, this is considered a desirable design paradigm, not a problem.
If you happen to be controlling several resources, the "finally" way
marches off the right side of the page -

	try {
		// acquire resorce 1
		try {
			// acquire resource 2
			try {
				// acquire resource 3
				// now do something
			} finally {
				// release resource 3
			}
		} finally {
			// release resource 2
		}
	} finally {
		// release resource 1
	}

As opposed to

	Res1Holder r1; // acquire resource 1
	Res2Holder r2; // acquire resource 2
	Res3Holder r3; // acquire resource 3

	// do something