Real cost of C++ exception vs error-code checking

Post by blub » Wed, Mar 09, 2011, 8:08 AM UTC

cpeterso wrote: post #49

AshleysBrain wrote: post #7

Earlier quoted context omitted.

This reads to me like 'writing good code is hard, and writing even better code is even harder'. With modern C++0x smart pointers (like unique_ptr) and RAII, you can get very high performance and (more) easily exception-safe code. Maybe a lot of C++ exception criticism comes from people still trying to code like C in C++?

But your exception-safe C++ code soon becomes bloated with shared_ptr and unique_ptr templates and copy ctors. Almost any C++ function, overloaded operator, or some implicit temporary object's ctor can throw an exception without warning. You must use RAII everywhere for every "resource". Exception-safe RAII is pretty much an all-or-nothing affair.

Post by JoeAltmaier » Wed, Mar 09, 2011, 2:55 PM UTC

johnny531 wrote: post #52

JoeAltmaier wrote: post #47

Perhaps the worst problem with checking-vs-exceptions is, either solution dominates your code structure, obscuring the algorithm logic. The holy grail would be some method of ensuring the code cannot fail e.g. weirdly constrained argument semantics. Thus separating algorithm from constraints instead of shuffling them together on the page like a deck of cards.

If only c++ had some sort of static type system which could be leveraged to provide compile-time checks... But seriously, this is a large part of the power of c++'s type system. Taking the article's example, if the argument types were of (user class) 'non_zero_float', there's no possibility for error. You still have to check that your input is non-zero at some point, but you've now focused it into one place (the 'non…