What does static_assert do, and what would you use it for?

Question

Could you give an example where static_assert(...) (\'C++11\') would solve the problem in hand elegantly?

I am familiar with run-time assert(...)<

Answer 1

One use of static_assert might be to ensure that a structure (that is an interface with the outside world, such as a network or file) is exactly the size that you expect. This would catch cases where somebody adds or modifies a member from the structure without realising the consequences. The static_assert would pick it up and alert the user.