[Bug c++/15394] New: g++ fails to produce a static definition for static template member

[Bug c++/15394] New: g++ fails to produce a static definition for static template member

[razeh at yahoo dot com]

I am having trouble getting gcc 3.4.0 to produce a static definition
for a static member of a template class.  I have been following
the example giving in bug report 15006
(http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15006) for creating
the static definition.  However, after adding a main to the sample
code that references the static variables it appears to compile but not link.


The compiler:
razeh@terk:/home/host/razeh/testing$ gcc -v
Reading specs from
/usr/local/packages/gcc-3.4.0/lib/gcc/sparc-sun-solaris2.8/3.4.0/specs
Configured with: /home/host/ewolfe/gcc-3.4.0/configure
--prefix=/usr/local/packages/gcc-3.4.0 --disable-multilib --enable-languages=c,c++
Thread model: posix
gcc version 3.4.0

The test case:

template<class K, class V> class EST_THash;
class EST_String
{
public:
  void foobar() { }
};
class EST_Regex
{
public:
  void bar() { }
};
template<class K, class V>
class EST_THash {
public:
  static V Dummy_Value;
  static K Dummy_Key;
};

template <> EST_Regex * EST_THash< EST_String, EST_Regex * >::Dummy_Value;
template <> EST_String EST_THash< EST_String, EST_Regex * >::Dummy_Key;
template EST_Regex * EST_THash< EST_String, EST_Regex * >::Dummy_Value;
template EST_String EST_THash< EST_String, EST_Regex * >::Dummy_Key;

int main(int argc, char *argv[])
{
  EST_THash<EST_String, EST_Regex*> foo;
  foo.Dummy_Value->bar();
}

The problem:
razeh@terk:/home/host/razeh/testing$ g++ missingStatic3.C
Undefined                       first referenced
 symbol                             in file
EST_THash<EST_String, EST_Regex*>::Dummy_Value       /var/tmp//cccPQZFu.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status

-- 
           Summary: g++ fails to produce a static definition for static
                    template member
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: razeh at yahoo dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: sparc-sun-solaris2.8/
  GCC host triplet: sparc-sun-solaris2.8/
GCC target triplet: sparc-sun-solaris2.8/


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15394

[Bug c++/15394] g++ fails to produce a static definition for static template member

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-12 13:48 -------
That is because I was wrong you have to supply the full template declaration for the variables like the 
following:

template <class K, class V> V EST_THash< K, V >::Dummy_Value;
template <class K, class V> K EST_THash< K, V >::Dummy_Key;

template EST_Regex * EST_THash< EST_String, EST_Regex * >::Dummy_Value;
template EST_String EST_THash< EST_String, EST_Regex * >::Dummy_Key;

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15394

[Bug c++/15394] g++ fails to produce a static definition for static template member

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-05-12 13:55 -------
No, Andrew, you are wrong again, but the code is invalid anyway. What 
happens is that 
 
  template <> type Class<type>::member; 
 
declares the existence of an explicit specialization of the member variable. 
You can do that, there is no requirement that only the completely 
unspecialized template class member variable can be declared. However, since 
this syntax is the _declaration_ of a variable, not a _definition_, you get 
a linker error. To make it a definition, you have to give the variable 
declaration an initializer, i.e. do something like 
   
  template <> type Class<type>::member = 1; 
 
or (if you want the default initialization): 
 
  template <> type Class<type>::member = type(); 
 
This will yield a _definition_ and should make the linker error go away. 
 
Wolfgang 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15394

[Bug c++/15394] g++ fails to produce a static definition for static template member

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-05-13 02:11 -------
Wolfgang is right, and before anybody asks, no, there is no way to define a of 
a specialized member variable without giving it an initializer, because the 
syntax clashes with the specialization declaration, and it is always resolved 
as the latter.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15394

[Bug c++/15394] g++ fails to produce a static definition for static template member

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-26 14:55 -------
*** Bug 22191 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bin-krzysiek at poczta dot
                   |                            |gazeta dot pl


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15394