On 7/19/06, Alexander Nasonov <alnsn@yandex.ru> wrote:
I don't know a practical value of this library except probably a management of exception handlers order [...]
While this library is mostly a solution in search of a problem, I see at least a good pratical use for this. Consider a library Foo that can work both by trowing exceptions or by returning error codes (for example for perceived better performance). The return codes, instead of being a set of values, are a set of types and are returned as a variant. This means that the user of library Foo can use the exception visitor both as a variant visitor and as an exception visitor. With appropriate infrastructure, the same code can work both if the library Foo uses exceptions or uses return codes (for example, you may use exceptions by default and convert to return codes in the critical paths or where error are common and expected, with minimal changes in code). Of course Foo would use the same types both as exceptions types and as result types. I have done this once and it kind of work well. -- Giovanni P. Deretta