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* [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic
@ 2006-07-10 20:11 igodard at pacbell dot net
2006-07-10 20:11 ` [Bug c++/28330] " igodard at pacbell dot net
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: igodard at pacbell dot net @ 2006-07-10 20:11 UTC (permalink / raw)
To: gcc-bugs
The error is an invocation of operator<<(ring<cacheRequest>&, loadRequest*).
ring<cacheRequest> defines operator<<(ring<cacheRequest>&, cacheRequest*), and
cacheRequest is a public base of the actual loadRequest argument. If the right
argument is explicitly cast to cacheRequest* (as shown in the line immediately
before the reported error) the correct operator<< is found and invoked.
However, when the argument is the derived class the compiler finds and invokes
an irrelevant definition of operator<< and then blows up inside it. The
definition it finds is declared by template wideUint<size_t> and in particular
by wideUint<1>: operator<<(wideUint<1>, const uint32_t&). Somehow it seems to
decide that it can turn a ring<cacheRequest>& into a wideUint<1>, and then
complains that it can't turn a cacheRequest* into a uint32_t (which is a
typedef
for unsigned int).
It seems to me that the compiler should be able to match the intended operator
by converting to the base class. However, even if it cannot then shouldn't it
just say "no match found for ..." rather than accepting the bogus match and
then
complaining about the conversion to uint32_t?
--
Summary: finds wrong template overload; peculiar diagnostic
Product: gcc
Version: 4.0.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: igodard at pacbell dot net
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/28330] finds wrong template overload; peculiar diagnostic
2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
@ 2006-07-10 20:11 ` igodard at pacbell dot net
2006-07-10 20:12 ` igodard at pacbell dot net
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: igodard at pacbell dot net @ 2006-07-10 20:11 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from igodard at pacbell dot net 2006-07-10 20:11 -------
Created an attachment (id=11855)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11855&action=view)
compiler output -v
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/28330] finds wrong template overload; peculiar diagnostic
2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
2006-07-10 20:11 ` [Bug c++/28330] " igodard at pacbell dot net
@ 2006-07-10 20:12 ` igodard at pacbell dot net
2006-07-11 8:29 ` bangerth at dealii dot org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: igodard at pacbell dot net @ 2006-07-10 20:12 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from igodard at pacbell dot net 2006-07-10 20:11 -------
Created an attachment (id=11856)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11856&action=view)
save-temps source (compressed)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/28330] finds wrong template overload; peculiar diagnostic
2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
2006-07-10 20:11 ` [Bug c++/28330] " igodard at pacbell dot net
2006-07-10 20:12 ` igodard at pacbell dot net
@ 2006-07-11 8:29 ` bangerth at dealii dot org
2008-03-02 10:57 ` truedfx at gentoo dot org
2009-12-08 21:07 ` redi at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: bangerth at dealii dot org @ 2006-07-11 8:29 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from bangerth at dealii dot org 2006-07-11 08:29 -------
As usual, a reduced (or at least smaller than 51,000 lines) testcase would be
supremely helpful...
W.
--
bangerth at dealii dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bangerth at dealii dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/28330] finds wrong template overload; peculiar diagnostic
2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
` (2 preceding siblings ...)
2006-07-11 8:29 ` bangerth at dealii dot org
@ 2008-03-02 10:57 ` truedfx at gentoo dot org
2009-12-08 21:07 ` redi at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: truedfx at gentoo dot org @ 2008-03-02 10:57 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from truedfx at gentoo dot org 2008-03-02 10:57 -------
I only came across this bug looking for something else, but anyway, here's a
reduced testcase:
template <typename T>
class ring {};
template <typename T>
ring<T> &operator<<(ring<T>&, T *);
class base {};
class derived : public base {};
void f() {
ring<base> r;
derived *d;
r << d;
}
I believe this code is invalid. The template argument can't be deduced, and
you'd need something like
template <typename T>
class ring {};
template <typename T>
struct non_deducible { typename T type; };
template <typename T>
ring<T> &operator<<(ring<T>&, typename non_deducible<T>::type *);
so that only the first argument is considered when choosing which T to use.
Or, more simply, make operator<< a member function.
--
truedfx at gentoo dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |truedfx at gentoo dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/28330] finds wrong template overload; peculiar diagnostic
2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
` (3 preceding siblings ...)
2008-03-02 10:57 ` truedfx at gentoo dot org
@ 2009-12-08 21:07 ` redi at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: redi at gcc dot gnu dot org @ 2009-12-08 21:07 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from redi at gcc dot gnu dot org 2009-12-08 21:06 -------
Assuming that's an accurate reduction of the original code, comment 4 is
correct. I didn't look at the preprocessed source, it includes Boost code that
will be very specific to the GCC 4.0.2 version it was compiled with and so
useless with any other version of GCC
--
redi at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28330
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-12-08 21:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2006-07-10 20:11 [Bug c++/28330] New: finds wrong template overload; peculiar diagnostic igodard at pacbell dot net
2006-07-10 20:11 ` [Bug c++/28330] " igodard at pacbell dot net
2006-07-10 20:12 ` igodard at pacbell dot net
2006-07-11 8:29 ` bangerth at dealii dot org
2008-03-02 10:57 ` truedfx at gentoo dot org
2009-12-08 21:07 ` redi at gcc dot gnu dot org
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