Can anyone explain C++ exception specifications to me?

Question

Can anyone explain Exception Specifications as used in C++ ?

• When are they used (I have rarely seen it used in code)
• What are the pros and cons (benefits/

Answer 1

Basically, exception specifications allow the compiler to optimize the stack. The disadvantage is that it's a hell of a lot of extra spec. This means that you commonly see it in library work but not so much in working code.

I believe there's also some compile-time exception-safety thing going on, but since I've never used it, I can't be sure.