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Subject: Re: [boost] [locale] Review part 1: headers
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2011-04-09 16:47:04

On 09/04/2011 20:29, Artyom wrote:
>>>> line 646: Normally it's undefined behavior to
>>>> dereference an iterator like this. I would
>>>> prefer an assert to throwing an exception.
>>> The point is that these locations are valid
>>> positions just you can't call operator*.
>>> I think it is better behavior because it
>>> is quite easy to make a mistake with this.
>>> (From my experience with this)
>> Of course, it's a good thing to detect
>> the error. The thing is that an exception
>> means that you unwind the stack, possibly
>> handling the exception at a higher level.
>> That's normally not the correct response
>> for a programming error.
> It is similar to std::vector's at()...
> Maybe, in any case I had found exception helpful,
> especially in situation when you don't a error in some part
> to shutdown entire process.
> Defensive but forgiving programming.

Definitely a no-no.
Dereferencing an invalid iterator is a programming error, not an
exceptional situation.

The thing to use is an assertion.

When your code is statically wrong, the compiler refuses to generate a
binary. Likewise, when your code is dynamically wrong, it just terminates.

Fix your code such that such situations may *never* happen. An exception
is something that *could* happen, even in bug-free software, like a
failure to perform an operation due to lack of the necessary resources.

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