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Internet Message Format | 1996-08-05 | 1.6 KB

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From: "Paul D. DeRocco" <[e-mail]>
Newsgroups: comp.lang.c++
Subject: Re: Exceptions and operator new. Help
Date: Sat, 17 Feb 1996 04:30:46 -0500
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You don't have to do that. Allocation and construction are treated as a
unit by the compiler. If operator new throws an exception, nothing will
happen. If the constructor throws an exception, operator delete will
automatically be called before the exception is propagated. If there are
class members that have destructors and you throw an exception after
some of them have been successfully constructed, the compiler will
ensure that the constructed ones will be destroyed and the unconstructed
ones won't. And if you're dealing with derived classes, an exception
that is thrown by a derived class constructor will call the destructors
for all the base and less-derived classes.

In other words, it works the way it "should."

By the way, if you don't need to handle xalloc locally, but m_pVarList
is a global that needs to be nullified in case the allocation fails,
simply nullify it first:

    m_pVarList = NULL;
    m_pVarList = new char[10];

If the allocation throws an exception, it will never return, so the
second store into m_pVarList won't happen.

--

Ciao,
Paul D. DeRocco