BUG: C2483 Instantiating Objects with the Thread Attribute

• The Microsoft C/C++ Compiler (CL.EXE), included with: - Microsoft Visual C++ 32-bit Edition, versions 1.0, 2.0, 4.0, 4.1, 4.2,

       5.0
  

SYMPTOMS

Instantiating a C++ object with the thread attribute generates the following error message if the class contains private or protected members:

   error C2483: object with constructor cannot be declared 'thread'

CAUSE

Currently, thread local storage has only been implemented for aggregate types. An aggregate type is defined as an array or object of a class with no constructors, no private or protected members, no base classes, and no virtual functions. In this case, private or protected members make the class an aggregate; therefore, the error message is generated.

RESOLUTION

To avoid this error, make all private or protected members of the class public members.

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The sample code below demonstrates how to produce and avoid the error message. Uncomment the "public" keyword before the data member to avoid the error.

Sample Code

   /* Compile options needed: /c /MT
   */

   class B
   {
   // Uncomment the following line to eliminate compiler error
   // public:
         int i;
   };

   __declspec(thread) B b; // error C2483