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Re: Const reference passing in constructor

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On 06/21/2011 02:39 PM, Rahul Karnik wrote:
> Hi,
>
> I get a runtime error with the following code:
>
> #include<iostream>
>
> using namespace std;
>
> class B {
> 	const A&  myA;
>
> public:

Try putting explicit constructor for B to get compile
error.

> 	B(const A&  anA);
> 	int getn() const { return myA.getn(); };
> };
>
> B::B(const A&  anA) : myA(anA) {}
>
> class C {
> 	const A&  myA;
> 	const B&  myB;
>
> public:
> 	C(const A&  anA);
> 	int getn() const { return myB.getn(); };
> };
>
> C::C(const A&  anA) : myA(anA), myB(myA) {}

Problem is here. B temporary is constructed from A reference
and then bound to const B reference .
Since temporary is destructed after constructing D object,
later on you have dangling reference.

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Const reference passing in constructor Rahul Karnik <rahul@genebrew.com> - 2011-06-21 05:39 -0700
  Re: Const reference passing in constructor Branimir Maksimovic <bmaxa@hotmail.com> - 2011-06-21 15:20 +0200
  Re: Const reference passing in constructor "Paul" <pchristor@yahoo.co.uk> - 2011-06-21 14:47 +0100

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