Object Swapping Part 1: Its Surprising Importance

To emphasize the fundamental nature of swap(), I've coined to the term "swapparator" in my Exception-Safe Coding talk. There is a video of my talk here: http://exceptionsafecode.com

Hello,
Either I missed something or it is the well known copy&swap idiom (http://en.wikibooks.org/wik...

This is old news, but nevertheless still doesn't get the attention it should in modern C++ design, so thanks for the refresher.

With C++11 there's a new reason to make "swap" a first-class citizen next to constructors, destructors and assignment operator: "Unifying assgiment"
http://en.wikibooks.org/wik...

For reference Herb Sutter on implementing assigment in terms of "swap" and it's benefit for exception safety:
http://www.gotw.ca/gotw/059...

It's an interesting idea and a common approach to implement a new component by using existing components; but in this case, why not just treat copy, assignment, and swap as three basic object operations on their own?

This is good food for thought. You've made a good argument for exception handling.

I don't quite see this as a general purpose solution however.

I'll be interested to see how this could improve performance. I can imagine scenarios where this could temporarily improve performance, by deferring the destruction of child objects and the freeing of resources until after the meaty work is done.

For that you'd likely want most of your data laden members to be pointers, so that they can be swapped between objects with minimal overhead.

I'm drawing a blank on other scenarios that would benefit, as you seem to be increasing the amount of work done in an assignment, without eliminating any pre-existing steps. You've just changed the order.