Knowledge Base

FIX: C2466: Using New to Allocate an Array of Size Zero

Article ID: 123811

Article Last Modified on 7/5/2005

Microsoft C++ 32-bit Compiler 1.0
Microsoft C/C++ Professional Development System 7.0
Microsoft Visual C++ 1.0 Professional Edition
Microsoft Visual C++ 1.5 Professional Edition
Microsoft Visual C++ 1.51

This article was previously published under Q123811

SYMPTOMS

If a constant expression that evaluates to zero is used to allocate an array, the following error occurs:

error C2466: cannot allocate an array of constant size 0

RESOLUTION

To work around the problem, use a variable that is initialized to zero in place of the constant when allocating the array.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++, 32-bit Edition, version 2.0.

MORE INFORMATION

The operator new() can be called with the argument zero. A distinct (non- null) pointer to an object will be returned (see Section 5.3.3 of the ARM - M.A.Ellis, B.Stroustrup). This is the behavior observed with Visual C++ version 2.0.

The following sample code can be used to demonstrate the problem.

Sample Code to Reproduce Problem

/* Compile options needed: none
*/ 

char * p = new char[0];  // Causes C2466

Additional query words: 1.00 1.50 7.00 8.00 8.00c

Keywords: kbbug kbfix kbcpponly kbcompiler KB123811