IV10074: EXPLICIT SPECIALIZATION FUNCTION ERROR

November 2011 PTF for XL C/C++ for AIX, V11.1
January 2012 PTF for XL C/C++ for AIX, V11.1
April 2012 PTF for XL C/C++ for AIX, V11.1
July 2012 PTF for XL C/C++ for AIX, V11.1
October 2012 PTF for XL C/C++ for AIX, V11.1
February 2013 PTF for XL C/C++ for AIX, V11.1
XL C/C++ for AIX Fix Pack 14 (May 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 22 (September 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 24 (September 2016 PTF) for 11.1

APAR status

• Closed as program error.

Error description

• When creating an instantiation of a normal template class that
  uses a static member function from a different, explicit
  specialization template class, the compiler is incorrectly
  generating an error.
  
  This incorrect behaviour is demonstrated in the following test
  case, where the explicitly specialized template class's primary
  template class does not have a definition, but the explicit
  specialization does.
  
  This is valid, because the definition of an explicitly
  specialized template class is unrelated to the definition of the
  primary template.  The primary template is not required to be
  defined in order to define the specialization.
  
  
     =====  TEST CASE  =====
  
  template <class T>
  class MyClass
  {
   private:
    static int const value;
  };
  
  template <class T> struct ExpSpec;
  //template<class T> struct ExpSpec { };  // primary template
  // Uncomment the primary definition, and the test case passes
  
  template<> // explicit specialization template
  struct ExpSpec<unsigned int>
  {
    static int getvalue() { return 7; }
  };
  
  template <class T>
  int const MyClass<T>::value = ExpSpec<T>::getvalue();
  
  
  template class MyClass<unsigned int>; // instantiation
  
  
     =====  Compile  =====
  
  $ xlC -c test.cpp
  "test.cpp", line 19.31: 1540-0062 (S) The incomplete class
  "ExpSpec" must not be used as a qualifier.
  $
  

Local fix

• Add a stub definition for the primary template class.
  

Problem summary

• PROBLEM DESCRIPTION:
  A compiler parsing error on an initializer for an out-of-line
  definition of a template member variable.
  
  USERS AFFECTED:
  The problem will only affect initializers which have a template
  name in the qualifier.
  

Problem conclusion

• The problem has been resolved, and the compiler no longer emits
  the error.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  LI76253

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL C/C++ AIX

• Fixed component ID

  5724X1300

Applicable component levels

• RB10 PSN U848679

     UP06/09/13 C