Re: Exceptions & Constructors

From:
"Xavier Serrand" <xxxxxx.xxxxxxx@xxx.fr>
Newsgroups:
comp.lang.c++
Date:
Mon, 30 Jul 2007 20:50:14 +0200
Message-ID:
<46ae32cb$0$25943$ba4acef3@news.orange.fr>
<jalqadir@gmail.com> a ?crit dans le message de
news:1185794153.322347.136860@l70g2000hse.googlegroups.com...

The constructor in MyClass instantiates many objects pointers through
'new', I would like to implement a way to make sure that the object
has been allocated in memory by catch(ing) the bad_alloc exception
error, but this means that I have to throw this error back from
MyClass constructor, how can I avoid this?

Thanks folks!


If you mind, a static function could be used... returning NULL in case of
failure...

Just like that :

   template <typename T> static Pile<T> * createPile(int sz)
   {
      Pile<T> * pp;
      try
      {
          pp = new Pile<T>(sz);
          return pp;
      }
      catch (std::bad_alloc&)
      {
         try
         {
           // clearing what can be cleared ...
           // ...
          // deleting the instance : the destructor has to be sure
          // (may be hard to do...)
            pp->~Pile<T>();
         }
         catch (std::exception& e)
         {
            // nothing to do
         }
         return NULL;
      }
   }

But remember what Alf P. Steinbach said !!

Xavier

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