[Bug c++/17037] New: static map in template crash on runtime when inserting

[Bug c++/17037] New: static map in template crash on runtime when inserting

[florent dot gallet at orange dot fr]

I use the mingw version of g++ 3.4.1 on windowsXP
Maybe my code is wrong but g++ should have say it before compiling and linking.
Don't know if this bug is on other version.
Here is how to reproduce the bug :

#include <iostream>
#include <map>

using namespace std;

struct ltstr
{
  bool operator()(const char* s1, const char* s2) const
  {
    return strcmp(s1, s2) < 0;
  }
};

template <typename _dxty>
class f
{
    public:
    typedef map<const _dxty*, int, ltstr > mapType;

    protected:
    static mapType months;

    public:
    f()
    {
      cout << "beginning" << endl;
      months["toto"] = 1;
      
      cout << "crash when inserting, same thing with insert" << endl;
    }
};

// this is maybe wrong but it compile and link this way
template class f<char>;
template <> f<char>::mapType f<char>::months;

int main()
{
    f<char> a;
    cin.get();
    return 0;
}

-- 
           Summary: static map in template crash on runtime when inserting
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: florent dot gallet at orange dot fr
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17037

[Bug c++/17037] static map in template crash on runtime when inserting

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-08-15 19:59 -------
The code is invalid in a number of ways about which the compiler 
can't do much. First, with this line: 
  template <> f<char>::mapType f<char>::months; 
This declares the _existence_ of a specialization. It does not 
_define_ it. 
 
The second bug is that you declare the specialization _after_ explicit 
instantiation of the class. The standard doesn't allow it. Since you 
do so, the compiler also can't warn you that that symbol doesn't exist, 
since it already instantiated it.  
 
For both these cases, no diagnostics are required. 
 
If you fix your code, the program runs just fine. 
 
W. 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17037

[Bug c++/17037] static map in template crash on runtime when inserting

[florent dot gallet at orange dot fr]

------- Additional Comments From florent dot gallet at orange dot fr  2004-08-15 21:41 -------
Sorry if my code is wrong, I was trying to convert old code, but I really 
don't see where's the prob :(

2 things :
- first: sorry for "template class f<char>;" it was in the other code (forgot 
to remove it to make this small piece of code)

- second: before I've tryed :
template f<char>::mapType f<char>::months;
or even
template class f<char>::mapType f<char>::months;
// error: explicit instantiation of `f<char>::months' but no definition 
available
and
template f<char>::mapType f<char>::months;
template <> f<char>::mapType f<char>::months;
or
template <> f<char>::mapType f<char>::months;
template f<char>::mapType f<char>::months;

but it crash the same way so I've removed it to make a smaller code

If you know how to do I'd really like to know because I'm becoming a little 
confused with the new syntax :S

And thanks to help me :)

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17037

[Bug c++/17037] static map in template crash on runtime when inserting

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-08-15 22:52 -------
This is the syntax to use: 
 
template <typename T> typename f<T>::mapType f<T>::months; 
template class f<char>; 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17037

[Bug c++/17037] static map in template crash on runtime when inserting

[florent dot gallet at orange dot fr]

------- Additional Comments From florent dot gallet at orange dot fr  2004-08-15 23:26 -------
It works :)
(I'll test in my project)

Sorry to have bothered you, I really thought, it could be a bug :S

Thanks again

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17037