On Tue, Nov 25, 2008 at 4:25 PM, Peter Dimov <pdimov@pdimov.com> wrote:
When Alisdair asked me to comment on the nested_exception paper, I suggested that it needs to be folded into std::exception, providing
std::exception_ptr std::exception::context() const;
that returns the value of std::current_exception() at construction time. This was (unfairly - IMHO) rejected for ABI reasons. With that in mind,
Emil Dotchevski:
What's wrong with
struct whatever { }; struct translated: boost::exception, std::exception { };
typedef boost::error_info<struct tag_nested_exception,boost::exception_ptr> nested_exception;
.... catch( whatever & e ) { throw translated() << nested_exception(boost::copy_exception(e));
I'd say that this needs to be:
throw translated() << context( boost::current_exception() );
The problem is that boost::current_exception may not always be able to get you the correct exception type (so far we only have Antony's implementation for MSVC which I haven't yet integrated in boost::exception, and which doesn't work in 64-bit builds AFAIK.) Certainly, if we're considering some 3rd party library which throws exceptions using throw directly, boost::current_exception won't do -- you need to catch this and that and use boost::copy_exception. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode