🚀 go-pugleaf

Hi,

auto_ptr doesn't seem to be usable for array objects...

Fergus Henderson (fjh@munta.cs.mu.OZ.AU) wrote:
: Use the following instead:
: 
: 	class a {
: 	public:
: 		auto_ptr<char> mBuffer1;
: 		auto_ptr<char> mBuffer2;
: 		a();
: 		~a();
: 	}
: 
: With auto_ptr, this becomes just
: 
: 	a::a()
: 	{
: 	  mBuffer1 = new char[1000];
: 	  mBuffer2 = new char[1000];
: 	}
: 
: or alternately
: 
: 	a::a()
: 	: mBuffer1(new char[1000]),
: 	  mBuffer2(new char[1000])
: 	{}
: 
: With auto_ptr, you don't even need a destructor - the compiler-generated
: one will do the right thing.

I doubt this statement. Doesn't this result in "undefined behavior"?

	[Moderator's note: yes, you're absolutely right.  My mistake.
		-fjh.]

According to lib.auto.ptr.cons the destructor of auto_ptr results in
"delete get()". But applying "operator delete" to an array object (the
result of "new char[1000]" is an array object: expr.new verse 7) yields
undefined behavior (expr.delete). Is this yet another problem for the
auto_ptr class that it can't deal with array objects or am I missing
something (maybe I'm not up to date with the latest state of the
standard...)?

dk
--
http://www.informatik.uni-konstanz.de/~kuehl
dietmar.kuehl@uni-konstanz.de
I am a realistic optimist - that's why I appear to be slightly pessimistic
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