This is actually a terrible idea, and I would suggest that we should not only reject it, but disallow it and actively edit people's answers to NOT have it.

Despite how much you want to argue about PHP having moved on, the rest of the world clearly has not. PHP 5.2 is still actively used by more than 60% of WordPress installs (source: http://wordpress.org/about/stats/ ).

So the upshot of the suggestion is that you want to actively make code in answers not work for the majority of the user base. This is problem 1.

The result of this would eventually be people saying "this code broke my site" and other people responding with "take out the namespace declaration and it will work fine". This is problem 2.

As a result of problem 2, you are introducing code to the public which, after being "fixed" by well-meaning users who are just looking for solutions to their problems, have inadvertently introduced non-prefixed code into their installations, polluting their global namespace, and potentially introducing even more problems down the line from having all these hastily named functions in there. Let's call this problem 3.

So there's three problems with the idea. In my view, any one of these problems is enough to reject the concept entirely.

Namespaces are a great idea. But introducing them as some kind of active attempt to force the majority to upgrade, well, that isn't as great of an idea.

This is actually a terrible idea, and I would suggest that we should not only reject it, but disallow it and actively edit people's answers to NOT have it.

Despite how much you want to argue about PHP having moved on, the rest of the world clearly has not. PHP 5.2 is still actively used by more than 55% of WordPress installs.

^{Oct 23, 2013}

So the upshot of the suggestion is that you want to actively make code in answers not work for the majority of the user base. This is problem 1.

The result of this would eventually be people saying "this code broke my site" and other people responding with "take out the namespace declaration and it will work fine". This is problem 2.

As a result of problem 2, you are introducing code to the public which, after being "fixed" by well-meaning users who are just looking for solutions to their problems, have inadvertently introduced non-prefixed code into their installations, polluting their global namespace, and potentially introducing even more problems down the line from having all these hastily named functions in there. Let's call this problem 3.

So there's three problems with the idea. In my view, any one of these problems is enough to reject the concept entirely.

Namespaces are a great idea. But introducing them as some kind of active attempt to force the majority to upgrade, well, that isn't as great of an idea.