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c++.beta - class template partial specialization

reply Christof Meerwald <cmeerw web.de> writes:
Hi,

#include <typeinfo>
#include <stdio.h>

template<class T>
struct A
{
  static void f()
  {
    printf("%08x %s\n", &A::f, typeid(A).name());
  }
};

template<class T>
struct A<const T>
{
  static void f()
  {
    printf("const: %08x %s\n", &A::f, typeid(A).name());
  }
};

int main()
{
  A<int & const>::f();
  A<int &>::f();
  A<int & volatile>::f();
  A<int & const volatile>::f();

  return 0;
}


The output depends on the order of template instantiations, but I guess 
the primary class template should always be used in this example.


bye, Christof

-- 
http://cmeerw.org                                 JID: cmeerw jabber.at
mailto cmeerw at web.de
Aug 22 2003
parent Christof Meerwald <cmeerw web.de> writes:
On Fri, 22 Aug 2003 17:45:07 +0000 (UTC), Christof Meerwald wrote:

   A<int & const>::f();
   A<int &>::f();
   A<int & volatile>::f();
   A<int & const volatile>::f();


This one was probably ill-formed, see 8.3.2 References [dcl.ref]:

  "Cv-qualified references are ill-formed except when the cv-qualifiers are
  introduced through the use of a typedef (7.1.3) or of a template type
  argument (14.3), in which case the cv-qualifiers are ignored."


But this one should be ok (and it should always choose the primary
template):

#include <typeinfo>
#include <stdio.h>

template<class T>
struct A
{
  static void f()
  {
    printf("%08x %s\n", &A::f, typeid(A).name());
  }
};

template<class T>
struct A<const T>
{
  static void f()
  {
    printf("const: %08x %s\n", &A::f, typeid(A).name());
  }
};

template<class T>
struct B
{
  static void f()
  {
    A<T const>::f();
    A<T>::f();
    A<T volatile>::f();
    A<T const volatile>::f();
  }
};

typedef int &intref;

int main()
{
  A<intref const>::f();
  A<intref>::f();
  A<intref volatile>::f();
  A<intref const volatile>::f();

  B<int &>::f();

  return 0;
}


bye, Christof

-- 
http://cmeerw.org                                 JID: cmeerw jabber.at
mailto cmeerw at web.de

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Sep 06 2003