FIX: Failure To Call Destructor of Explicitly Constructed Anonymous Temporary (216731)

The information in this article applies to:

Microsoft Visual C++, 32-bit Enterprise Edition 6.0
Microsoft Visual C++, 32-bit Professional Edition 6.0
Microsoft Visual C++, 32-bit Learning Edition 6.0

This article was previously published under Q216731

SYMPTOMS

When an explicitly constructed anonymous temporary of template type that has a default constructor with a default argument is used in an expression, it is never destroyed.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base:

194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

MORE INFORMATION

Sample Code

#include <stdio.h>
const int ex = 4;

template<typename T>
struct CPtr {
    CPtr(int e = ex) {
		m_ptr = new T();
		printf("In CPtr::CPtr()\n");
	}

    T *operator->() const {
		return m_ptr;
	}

	~CPtr() {
		printf("In CPtr::~CPtr()\n");
	}

	T *m_ptr;
};

struct I {
	int mf() {return 1;}
};

int main()
{
	bool fFlag = false;
	if ((CPtr<I>()->mf() < 0) && !fFlag) return 1;
	return 0;
}

The output is:

In CPtr::CPtr()

The output should be:

In CPtr::CPtr()
In CPtr::~CPtr()

Modification Type:	Major	Last Reviewed:	11/18/2003
Keywords:	kbBug kbCompiler kbCPPonly kbfix kbVC600fix kbVS600sp3fix KB216731