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Error-Handling in Swift-Language
It doesn't have exception handling, and this discussion in the developer forum discusses why it may be so:
but keep in mind that Cocoa and Cocoa Touch traditionally don't intend for you to catch exceptions; they intend for you to not cause them to be thrown in the first place. Ordinary errors should be handled with optional types and inout NSError parameters; you should address any situation that causes an assertion to fail (which seems to be the only exception-throwing mechanism in Swift) by writing better code.
I believe that, as of today, Swift does not support this. It will most likely be added on future betas.