[Bug c++/20307] New: template resolution is wrong when accessed with namespace prefix

[Bug c++/20307] New: template resolution is wrong when accessed with namespace prefix

[vasilche at ncbi dot nlm dot nih dot gov]

In the program:
--------------
extern "C" int puts(const char*);

template<typename A, typename B>
void foo(A a, B b)
{
    puts("ERROR: foo<A, B>");
}

template<typename X>
void bar(X a)
{
#ifdef ERROR
    ::foo(a, a);
#else
    foo(a, a);
#endif
}

template<typename A>
void foo(A a, A b)
{
    puts("OK: foo<A>");
}

int main()
{
    int a = 0;
    bar(a);
}
---------------
When foo<> template is accessed without namespace qualifier from within bar<>
template, GCC selects correct second variant of template variant.
If I put namespace qualifier gcc chooses the first variant.
This bug appeared with gcc 3.4 and exists in 3.4.1-3.4.3.
I didn't check newer versions.
There was no this bug in gcc 2.95-3.3.3.
Intel, Sun, and MS compilers all choose correct second variant of foo<>.

-- 
           Summary: template resolution is wrong when accessed with
                    namespace prefix
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: vasilche at ncbi dot nlm dot nih dot gov
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: 3.4.0-3.4.3
  GCC host triplet: Linux widget1 2.4.23-P4-4G #8 SMP Tue Dec 16 16:34:15
                    EST 2003 i


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20307

[Bug c++/20307] template resolution is wrong when accessed with namespace prefix

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-03 22:54 -------
Nope, qualified names bind right away, see PR 11828.
And from the standard:
>From [temp.dep.candidate]:
For a function call that depends on a template parameter, if the function name is an "unqualified-id" 
but not a template-id, the candidate functions are found using the usual lookup rules (3.4.1, 3.4.2) 

*** This bug has been marked as a duplicate of 11828 ***

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20307

[Bug c++/20307] template resolution is wrong when accessed with namespace prefix

[smcpeak at cs dot berkeley dot edu]

------- Additional Comments From smcpeak at cs dot berkeley dot edu  2005-03-04 03:59 -------
Andrew, I think you are misinterpreting [temp.dep.candidate]
(14.6.4.2).  That section modifies the lookup rules for
unqualified-ids that are dependent, but does *not* say that only
unqualified-ids can be dependent.

I already posted a comment (#20) in PR 11282 that (among other
things) points this out, but no one has responded.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20307