"Iain K. Hanson" <[EMAIL PROTECTED]> writes: >> But is this a good design? It certainly isn't the only possible one. >> (Making all the code depend upon the definitions of both Network_err and >> File_system_err - which no doubt drags other stuff into the translation unit >> - isn't a design choice I'd make lightly.) > > In certain places it may be the most natural design choice. Whether it > is a good idea to pay for virtual inheritance in every exception derived > from class exception is a separate issue. Exception handling incurs a > significant cost once an exception is thrown. Adding to that cost could > drive more users away from exception handling.
Do you think dynamic downcasting through a layer of virtual inheritance is significantly more expensive than downcasting through a layer of regular inheritance? > Also, I'm not sure that this use case is sufficiently common to burden > all exceptions with. What's the burden? I'm just askin', is all. -- Dave Abrahams Boost Consulting www.boost-consulting.com _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
