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From: Ole-Hjalmar Kristensen
 <ole-hjalmar.kristensen@substitute_employer_here.com>
Newsgroups: comp.lang.ada
Subject: Re: memory management and productivity
Date: 22 Jun 2004 09:58:09 +0200
Organization: Sun Microsystems
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>>>>> "FJL" == Frank J Lhota <NOSPAM.lhota.adarose@verizon.net> writes:

    FJL> "Ole-Hjalmar Kristensen"
    FJL> <ole-hjalmar.kristensen@substitute_employer_here.com> wrote in message
    FJL> news:wvbrsmcp2uqd.fsf@europa1.Norway.Sun.COM...
    >> > Russ wrote:
    >> Yes, *IF* it has been allocated with new.

    FJL> In C++, all memory allocation / deallocation should be done using the new /
    FJL> delete operators. This is true even for pointers to classes that do not have
    FJL> constructors or destructors. This is because classes often have default
    FJL> constructor / destructor actions that need to be performed for the object to
    FJL> be usable. For example, if the class has any virtual methods, then "jump
    FJL> table" must be set up. Also, if any field / sub-field / sub-sub-field has a
    FJL> constructor / destructor, then this constructor / destructor cannot be
    FJL> ignored.

Yes, I agree. I was thinking about stack-allocated objects, where
the destructor is called automatically for you upon exit of the
varaible's scope.

    FJL> The safe way to change the memory management algorithms for a given C++
    FJL> class is to define new / delete operators for that class. This will permit
    FJL> the user-defined algorithms for allocation / deallocation to be used for the
    FJL> class without interfering with constructor / destructor actions. This is the
    FJL> C++ equivalent of the Ada "for Name'Storage_Pool use ...;" clause.

    >> This is exactly the same as C++.  I would say that Ada and C++ are
    >> more or less on equal footing when it comes to garbage collection in
    >> practice.

    FJL> I agree. It would be more accurate to say that in both Ada and C++, the
    FJL> tools are there to implement your types with GC.

Yes, that would be more accurate, although conservative collectors
like Boehm's would probably work with both languages.

-- 
   C++: The power, elegance and simplicity of a hand grenade.