[themartorana]

Writing high performance server software is a whole other world from writing services. In the first, data copies can cause unacceptable slow-downs of a fraction of a millisecond - and those copies may be hidden all the way down at the driver level. When writing services (which are just as often written in Ruby or Python) trading off a few milliseconds for safety is often a worthy thing.

I spend most of my time writing services, and when looking at a language like Go, there's a reason the default is pass-by-value. Passing around pointers to multiple co-routines is asking for a race condition, and in non-GC languages, null pointers. Services are rarely written with the precision of high-performance servers.

I don't envy the server writers (although I can see how it would be fun!). Giving up a few milliseconds per request to make sure my co-routines aren't sharing pointers is worthwhile, and I appreciate the safety that gives me. I'm sure someone will mention that Rust could give me the safety I was looking for in a non-GC language, but that's the point, isn't it - that by being able to game the system, you can gain a few precious microseconds here and there that enforced safety might cost you.

[kibwen]

  > I'm sure someone will mention that Rust could give me 
  > the safety I was looking for in a non-GC language, but 
  > that's the point, isn't it

I'm not sure what you're trying to say here. There is no need to game the system, as Rust lets you pass pointers between threads while enforcing that they are used safely. Rust lets you be as fast as an unsafe language while as safe as a managed language; the tradeoff is that you have to give more thought to your design up-front (which, given the pain of trying to reproduce and fix race conditions, is more than worth the effort IMO).