Re: Exception question

From:
Paavo Helde <nobody@ebi.ee>
Newsgroups:
comp.lang.c++
Date:
Wed, 06 Aug 2008 01:48:08 -0500
Message-ID:
<Xns9AF263B92DF31nobodyebiee@216.196.97.131>
junw2000@gmail.com kirjutas:

class A
{
public:
     A() { p_a = new int;}
     ~A() { delete p_a; } //Line1
private:
     int *p_a;
}


 missing ;

void f()
{
     try
     {
           A a1;
           cout << "In f()" << endl;
          g(); //Line2
          A a2;
     }
     catch()


You probably meant "catch(...)" here.

     {
          cout << "In catch" << endl;
     }
}

void g()
{
       cout << "In g()" << endl;
      throw; //Line3


You probably meant "throw 42;" here, throw without an argument can be
used only from inside a catch handler.

}

When an exception is thrown at Line3 in g(), stack will unwind at
Line2 in f(). When a1 is destructed, will Line1 be excecuted so that
p_a is deleted? How about a2?


Yes, the language is designed so that it would be possible to write
exception-safe code. a1 is destructed properly and a2 never gets created.

hth
Paavo

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