Knowledge Base

BUG: LNK2001 Error for Static Member in Class Template

Article ID: 151167

Article Last Modified on 12/2/2003

APPLIES TO

Microsoft Visual C++ 2.0 Professional Edition
Microsoft Visual C++ 2.1
Microsoft Visual C++ 2.2
Microsoft Visual C++ 4.0 Standard Edition
Microsoft Visual C++ 4.1 Subscription
Microsoft Visual C++ 4.2 Enterprise Edition
Microsoft Visual C++ 5.0 Enterprise Edition
Microsoft Visual C++ 4.2 Professional Edition
Microsoft Visual C++ 5.0 Professional Edition

This article was previously published under Q151167

SYMPTOMS

Linker error LNK2001 is generated for static member variables of nested classes in class templates. The message states:

error LNK2001: unresolved external symbol "public: static int Outer<int>::Inner::sobj"(?sobj@Inner@?$Outer@H@@2HA)

RESOLUTION

Do not use static member variables in nested classes of class templates.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

The sample code below gives the error message LNK2001.

Sample Code

/* Compile options needed: none
*/ 

template<class T> class Outer
{
public:
    static T souter;

    class Inner
    {
    public:
        static T sobj;
    };
};

template <class T> double Outer<double>::souter = 1;

template <class T> int Outer<int>::Inner::sobj = 5;

void main()
{
    double dval = Outer<double>::souter;

    int i = Outer<int>::Inner::sobj;
}

Additional query words: kbVC400bug

Keywords: kbbug kbcpponly kbcompiler KB151167