[Insight-users] throwing exception inside constructor

[Luis Ibanez]

Hi Ziv,

So, I was clearly wrong in my previous email.

It seems that your Exception should have worked fine
in the constructor.

Could you please post to the list a minimal source code
example that illustrate the crash that you are observing ?


We could then track the problem from there.


    Thanks


       Luis



------------------
Brad King wrote:
> Niels Dekker wrote:
> 
>>Luis Ibanez wrote:
>>
>>>Hi Ziv,
>>>
>>>Throwing exceptions from constructors is in general discouraged.
>>
>>It may be discouraged to throw exceptions from constructors of ITK based
>>objects (if you say so), but it certainly isn't discouraged "in general".
>>
>>Bjarne Stroustrup even recommends doing so!  From Bjarne's C++ Style and
>>Technique FAQ:  "You should throw an exception from a constructor
>>whenever you cannot properly initialize (construct) an object. There is
>>no really satisfactory alternative to exiting a constructor by a throw."
>>www.research.att.com/~bs/bs_faq2.html#ctor-exceptions
> 
> 
> This is correct.  Throwing from *destructors* is discouraged, and IMO
> should be outright banned by convention.  Throwing from constructors is
> the proper thing to do when the object cannot be initialized into a
> valid state.  Usually this means some resource could not be allocated.
> 
> The question here is whether ITK convention allows allocation of
> resources during construction (other than perhaps memory for sub-objects
> allocated dynamically).  Since there are no constructor arguments for
> objects in the LightObject hierarchy, I think the convention discourages
> allocation of resources by constructors.
> 
> -Brad
>