[Bug c++/20484] New: No proper linkage created for in class initialized static const

[Bug c++/20484] New: No proper linkage created for in class initialized static const

[dopheide at fmf dot nl]

Example:
template <typename T>
T const max1(T const a, T const b)
{ return a < b ? b : a; }

template <typename T>
T const & max2(T const & a, T const & b)
{ return a < b ? b : a; }

struct Test
{ static int const A = 1; };

int main()
{
#if 0
  max1(Test::A, 2);     // OK.
#else
  max2(Test::A, 2);     // Does not link: undefined reference to `Test::A
#endif
}

The problem does not appear in 2.95.4
The problem does appear in 3.0.4, 3.2.3
Also appeared on 3.4.4 x86_64

-- 
           Summary: No proper linkage created for in class initialized
                    static const
           Product: gcc
           Version: 3.3.5
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dopheide at fmf dot nl
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i486-linux
  GCC host triplet: i486-linux
GCC target triplet: i486-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20484

[Bug c++/20484] No proper linkage created for in class initialized static const

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-15 16:12 -------
You need to declare space for the variable still like so:
int const Test::A;

This is invalid.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20484

[Bug c++/20484] No proper linkage created for in class initialized static const

[dopheide at fmf dot nl]

------- Additional Comments From dopheide at fmf dot nl  2005-03-15 18:46 -------
You are correct. I was wrong.

I thought, because of consistency reasons, that
1) both should link, or
2) both shouldn't link.
(And I choose 1) for the "bug"-report.)

As I now understand it, the "static int const A = 1;" will be seen as an
"integral constant expression". If, OTOH, a reference has to be taken, it is
seen as a "normal int", thus requiring an actual definition. (It is in 9.4.2 of
the standard.)

See also bugs 14404, 13259, 15244, 17673.

(I search the bugs database before filing, but could not find it.)

It stills /looks/ inconsistent though.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20484

Re: [Bug c++/20484] No proper linkage created for in class initialized static const

[Andrew Pinski]

On Mar 15, 2005, at 1:46 PM, dopheide at fmf dot nl wrote:

> It stills /looks/ inconsistent though.

That is because there is an optimization going on here which is allowed
by the standard.


-- Pinski

[Bug c++/20484] No proper linkage created for in class initialized static const

[pinskia at physics dot uc dot edu]

------- Additional Comments From pinskia at physics dot uc dot edu  2005-03-15 18:50 -------
Subject: Re:  No proper linkage created for in class initialized static const


On Mar 15, 2005, at 1:46 PM, dopheide at fmf dot nl wrote:

> It stills /looks/ inconsistent though.

That is because there is an optimization going on here which is allowed
by the standard.


-- Pinski



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20484