In one of my projects I have embedded a Perl interpreter into the main C++ application; I load (and eval) some external scripts at run-time and have no access to any module, even pragma ones (so no strict and vars). OTOH, I develop the scripts using strict, so I'm forced to declare all variables as lexically scoped.

To add flexibility, I keep some configuration variables declared at the beginning of the main script, and leave the possibility to change these configurations including other configuration scripts later. This is where our came to rescue me: my fails miserably, restricting scope to each single eval I call.

I know, it wasn't (probably) designed to solve my particular issue^* - just a real world example, though...

*To summarise, impossibility to use vars and multiple evals.