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

MS-DOS | WINDOWS        | WINDOWS NT

The information in this article applies to:

• The Microsoft C/C++ Compiler (CL.EXE) included with:

      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0, 1.5, and 1.51
      - Microsoft Visual C++, 32-bit Edition, version 1.0
  

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