* Possible bug in g++ - template specialization
@ 2009-07-10 11:48 Maciej Cencora
2009-07-10 12:44 ` Richard Guenther
0 siblings, 1 reply; 2+ messages in thread
From: Maciej Cencora @ 2009-07-10 11:48 UTC (permalink / raw)
To: gcc
Hi,
I think I've found a bug in g++. Let's say we have following files:
// a.hpp
template<typename T>
void func1()
{
// general code
}
// a.cpp
#include "a.hpp"
template<>
void func1<int>()
{
// specialized code
}
// main.cpp
#include "a.hpp"
int main(void)
{
func1<int>();
return 0;
}
Now when we run the program compiled with: g++ main.cpp a.cpp -o main
specialized version of func1 will be called, but when compiled with
-Os flag the general version will be called.
I'm not an expert but I believe the -Os behaviour is the correct one.
Please CC me when replying, as I'm not subscribed to the mailing list.
Regards,
Maciej Cencora
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Possible bug in g++ - template specialization
2009-07-10 11:48 Possible bug in g++ - template specialization Maciej Cencora
@ 2009-07-10 12:44 ` Richard Guenther
0 siblings, 0 replies; 2+ messages in thread
From: Richard Guenther @ 2009-07-10 12:44 UTC (permalink / raw)
To: Maciej Cencora; +Cc: gcc
On Fri, Jul 10, 2009 at 1:48 PM, Maciej Cencora<m.cencora@gmail.com> wrote:
> Hi,
>
> I think I've found a bug in g++. Let's say we have following files:
>
> // a.hpp
>
> template<typename T>
> void func1()
> {
> // general code
> }
>
> // a.cpp
>
> #include "a.hpp"
>
> template<>
> void func1<int>()
> {
> // specialized code
> }
>
> // main.cpp
>
> #include "a.hpp"
>
> int main(void)
> {
> func1<int>();
>
> return 0;
> }
>
>
> Now when we run the program compiled with: g++ main.cpp a.cpp -o main
> specialized version of func1 will be called, but when compiled with
> -Os flag the general version will be called.
> I'm not an expert but I believe the -Os behaviour is the correct one.
By not making the specialized version available at the point of
instantiation you are violating the one-definition rule (ODR, no need
to diagnose it) and the behavior is undefined.
Richard.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-07-10 12:44 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-07-10 11:48 Possible bug in g++ - template specialization Maciej Cencora
2009-07-10 12:44 ` Richard Guenther
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).