FW: [CST-2] Address taken variable

[Barnaby Gray]

Lame. Seriously lame.

Barnaby

On Thu, May 30, 2002 at 12:10:03AM +0100, Tom Puverle wrote:
> > An address taken variable is one whose address has been 'taken' by the
> > program (funnily enough!)
> > 
> > E.g. in C 
> > 
> >    a = &b;
> > 
> > we set a (usually a pointer) to the address of b :- b is address taken.
> 
> Sorry I misinterpreted your last post. 
> 
> Anyway, it has to be said that in C++ this syntax doesn't always imply
> the taking of the address of b, nor does it always imply an assignment to 
> a pointer variable a.
> As an example consider what happens if b is a variable of a class with 
> an overloaded operator&()
> 
> 	class SomeType
> 	{
> 		...
> 		public:
> 			int operator&()
> 			{
> 				hdd_->format();
> 				return 0;
> 			}
> 		private:
> 			BootHDD * hdd_;
> 			...
> 	
> 	};
> 
> 	void foobar()
> 	{
> 		SomeType b;
> 		int a = &b;		//doesn't quite do what you expect... :)
> 	}
> 
> There is also the other possibility of a not being a pointer type
> but a class with an overloaded operator=()
> 
> 
> 	class SomeOtherType
> 	{
> 		...
> 		public:
> 			SomeOtherType & operator=(int * rhs )
> 			{
> 				//do whatever		
> 			}
> 		...
> 	}
> 
> Then
> 
> 	void barfoo()
> 	{
> 		SomeType a;
> 		int b;
> 		a = &b;	
> 	}
> 
> again doesn't do exactly what you expect.
> However, I don't expect them to ask you this in the exam.
> Tom
> 
> 
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