Embedded C++ : to use STL or not?

I work on real-time embedded systems every day. Of course, my definition of embedded system may be different than yours. But we make full use of the STL and exceptions and do not experience any unmanageable problems. We also make use of dynamic memory (at a very high rate; allocating lots of packets per second, etc.) and have not yet needed to resort to any custom allocators or memory pools. We have even used C++ in interrupt handlers. We don't use boost, but only because a certain government agency won't let us.

It is our experience you can indeed use many modern C++ features in an embedded environment as long as you use your head and conduct your own benchmarks. I highly recommend you make use of Scott Meyer's Effective C++ 3rd edition as well as Sutter and Alexandrescu's C++ Coding Standards to assist you in using C++ with a sane programming style.

Edit: After getting an upvote on this 2 years later, let me post an update. We are much farther along in our development and we have finally hit spots in our code where the standard library containers are too slow under high performance conditions. Here we did in fact resort to custom algorithms, memory pools, and simplified containers. That is the beauty of C++ though, you can use the standard library and get all the good things it provides for 90% of your use cases. You don't throw it all out when you meet problems, you just hand-optimize the trouble spots.

The other posts have addressed the important issues of dynamic memory allocation, exceptions and possible code bloat. I just want to add: Don't forget about <algorithm>! Regardless of whether you use STL vectors or plain C arrays and pointers, you can still use sort(), binary_search(), random_shuffle(), the functions for building and managing heaps, etc. These routines will almost certainly be faster and less buggy than versions you build yourself.

Example: unless you think about it carefully, a shuffle algorithm you build yourself is likely to produce skewed distributions; random_shuffle() won't.

Super-safe & lose much of what constitutes C++ (imo, it's more than just the language definition) and maybe run into problems later or have to add lots of exception handling & maybe some other code now?

We have a similar debate in the game world and people come down on both sides. Regarding the quoted part, why would you be concerned about losing "much of what constitutes C++"? If it's not pragmatic, don't use it. It shouldn't matter if it's "C++" or not.

Run some tests. Can you get around STL's memory management in ways that satisfy you? If so, was it worth the effort? A lot of problems STL and boost are designed to solve just plain don't come up if you design to avoid haphazard dynamic memory allocation... does STL solve a specific problem you face?

Lots of people have tackled STL in tight environments and been happy with it. Lots of people just avoid it. Some people propose entirely new standards. I don't think there's one right answer.