Re: Question on vector at()
Alexander Dong Back Kim wrote:
try
{
return _appleBox.at(index);
}
catch (out_of_range e)
{
return ???;
}
Perhaps a different design could be better here?
Usually indexing out of boundaries means one of two things:
1) It's an error, ie. a bug in the code. In this case an assert() is
usually better than throwing (because you can get the whole call stack
easily with a debugger).
2) In a few designs it's not an error at all, but intended behavior. In
these cases usually indexing out of boundaries simply returns some
default value of the element type. In that case checking the boundaries
before indexing (and returning the default value if it's out of
boundaries) is better than using at(), which throws an exception.
A third possibility where and index may be in danger of being out of
boundaries is with invalid user input. However, throwing an exception in
this case would usually be very wrong. The correct way is to validate
the user input before even trying to index anything.
I can't think of many applications where at() throwing an exception
would be in any way a desirable thing. (As mentioned, to catch
programming errors IMO using assert() is better.)