Boost C++ Libraries: Ticket #9796: std::system_error cannot be catched after is rethrown with boost::rethrow_exception()

status changed; resolution set

Emil Dotchevski — Thu, 20 Mar 2014 18:28:56 GMT

status new → closed
resolution → invalid

I understand that in this case the throw site might not be in your code, but see http://www.boost.org/doc/libs/release/libs/exception/doc/enable_current_exception.html. If possible, use boost::throw_exception instead of throw.

anonymous — Fri, 21 Mar 2014 07:35:41 GMT

As I wrote this throw is from a std::library function (like for example std::thread().detach();, see [trac does not allow me to add links, so find it on google by yourself]), so throw_exception cannot be used.

Besides if you replace std::system_error with for example std::logic_error, the code works - the logic_error is properly catched. This means that this bug is not invalid. Please reopen it, and fix it.

status changed; resolution deleted

anonymous — Fri, 21 Mar 2014 07:36:11 GMT

status closed → reopened
resolution invalid

status changed; resolution set

Emil Dotchevski — Fri, 21 Mar 2014 20:51:35 GMT

status reopened → closed
resolution → invalid

From http://www.boost.org/doc/libs/release/libs/exception/doc/current_exception.html: "Whenever current_exception fails to properly copy the current exception object, it returns an exception_ptr to an object of type that is as close as possible to the original exception type, using unknown_exception as a final fallback." This is to say that your code must be prepared to deal with boost::current_exception failing to give you an object of the exact type.

(The std::logic_error exception is also not properly cloned which can lead to slicing. Similar support for std::system_error is more problematic because it isn't available in all implementations yet. Where it is available, in all likelihood std::current_exception is available as well, so just use that.)