Re: [Boost-users] [boost] [review][constrained_value] Review of Constrained Value Library begins today

David Abrahams wrote:

Exceptions should almost never be used in response to broken invariants.

Pardon my ignorance, but how come? The constraints I have to validate usually concern broken user input via the command line or a query string. How should I deal with them if not with exceptions? Or to be more precise, why should I not use constrained types for validating user input if it saves me a lot of if-statements in the long run? --> Mika Heiskanen