In .net why is throwing an exception computationally heavy?

Question

In .net why is throwing an exception computationally heavy?

Answer 1

Things like computing the full call stack at the exception point take time and computation.

However, there is some places where .NET does better than C++, since it doesn't have to track memory that needs to be cleaned up the same way as a C++ exception handler.

For some more details, I'd recommend Rico Mariani's blog post on this subject.