Marshall Clow <marshall <at> idio.com> writes:
gast128 <gast128 <at> hotmail.com> wrote:
Sutter has made a guideline for when to use exceptions and when not ("When
and
How to Use Exceptions", http://www.ddj.org/cpp/184401836). By using this guideline, programmers actually have to deal with two strategies instead of one, not to mention that writing excpetion safe code (without leaks) is very hard. If you get stuck you can always buy his books :)
Actually, having read all of Bruce's books Eh, isn't his name Herb...
, and having talked to him at a couple of conferences, I find that writing exception safe code is quite simple - once you have embraced RAII everywhere. You do have to think about exception safety, but for most routines that thinking boils down to "What happens if something throws here? Um, .... nothing bad.", since RAII ensures that no locals leak, and I can look at the global/parameter cases quickly. Not sure about that. I think you probably have to wrap every raw pointer in a smart pointer or ending up having try / catch everywhere. Writing everywhere try / catch doesn't improve the readability imo (which is also depreciated by people). Item 17-23 and item 29 of more exceptional c++ are all about case where exceptions occur, none of them are trivial (for me at least).
I find it also leads to simple, easy to write (and understand code). Sure? What if you make a pool of available devices like (COM ports) and they throw when not available (which btw raises the question if this an exceptional case or just common):
std::vector<Device*> v; for (int n = 0; n < nSize; ++n) { try { Device* pDevice = new Device(n); v.push_back(pDevice); } catch (...) { //not available } } is this more readable then: for (int n = 0; n < nSize; ++n) { std::auto_ptr<Device> ptrDevice(new Device(n)); if (ptrDevice->IsOk()) { v.push_back(ptrDevice.Release()); } } Probably I can predict your answer. If you write deep nested functions with clear entry points, these exception can really improve the code, but then you are using them as a pimped 'goto' statement, which was not the intention.