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* [Bug c++/52108] New: declval() with incomplete type
@ 2012-02-03 13:52 hidden_peak at mail dot ru
2012-02-03 14:37 ` [Bug c++/52108] " redi at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: hidden_peak at mail dot ru @ 2012-02-03 13:52 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52108
Bug #: 52108
Summary: declval() with incomplete type
Classification: Unclassified
Product: gcc
Version: 4.5.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: hidden_peak@mail.ru
Created attachment 26563
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26563
bug illustration
Wrong report about 'incomplete type'. Situation has relation to type selection
technique.
Key string in the example is
template <class T>
static decltype( declval<typename T::pointer>(), declval<true_type>())
__test_p( int );
First declval (declval<typename T::pointer>) and comma operator required for
problem demonstration. Another condition is usage of x-pair<int,Incomplete>.
For testcase, see attached file. Compilation:
c++ -std=gnu++0x -c test.cc
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/52108] declval() with incomplete type
2012-02-03 13:52 [Bug c++/52108] New: declval() with incomplete type hidden_peak at mail dot ru
@ 2012-02-03 14:37 ` redi at gcc dot gnu.org
2012-04-18 9:10 ` abominable-snowman at yandex dot ru
2012-04-18 10:36 ` redi at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: redi at gcc dot gnu.org @ 2012-02-03 14:37 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52108
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |rejects-valid
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-02-03
Ever Confirmed|0 |1
Known to fail| |4.6.2, 4.7.0
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-02-03 14:37:35 UTC ---
Confirmed, x_pair shouldn't be instantiated to form x_pair*
Reduced:
struct true_type { static const bool value = true; };
struct false_type { static const bool value = false; };
template <class T>
T&& declval() noexcept;
template <class T>
struct my_t_alloc_p
{
typedef T value_type;
typedef value_type* pointer; // <--- see Incomplete below
};
struct type_selector
{
#if 1
// T::pointer should be present
template <class T>
static decltype( declval<typename T::pointer>(), declval<true_type>())
__test_p( int );
#else
// If the declaration above re-write as below (worse, IMO), then it pass:
template <class T>
static decltype( T::pointer(), declval<true_type>() ) __test_p( int );
#endif
template <class>
static false_type __test_p( ... );
};
template <class Alloc>
struct x_allocator_traits
{
typedef decltype(type_selector::__test_p<Alloc>(0)) pointer;
};
template <class A>
struct x_pair
{
A a;
};
struct Incomplete
{
typedef typename x_allocator_traits<my_t_alloc_p<x_pair<Incomplete> >
>::pointer pointer6;
};
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/52108] declval() with incomplete type
2012-02-03 13:52 [Bug c++/52108] New: declval() with incomplete type hidden_peak at mail dot ru
2012-02-03 14:37 ` [Bug c++/52108] " redi at gcc dot gnu.org
@ 2012-04-18 9:10 ` abominable-snowman at yandex dot ru
2012-04-18 10:36 ` redi at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: abominable-snowman at yandex dot ru @ 2012-04-18 9:10 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52108
--- Comment #2 from Petr Ovtchenkov <abominable-snowman at yandex dot ru> 2012-04-18 09:09:04 UTC ---
There are opinion, that this is not a bug:
http://llvm.org/bugs/show_bug.cgi?id=12583
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/52108] declval() with incomplete type
2012-02-03 13:52 [Bug c++/52108] New: declval() with incomplete type hidden_peak at mail dot ru
2012-02-03 14:37 ` [Bug c++/52108] " redi at gcc dot gnu.org
2012-04-18 9:10 ` abominable-snowman at yandex dot ru
@ 2012-04-18 10:36 ` redi at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: redi at gcc dot gnu.org @ 2012-04-18 10:36 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52108
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |INVALID
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-18 10:22:33 UTC ---
I agree with Richard's analysis, I hadn't thought of operator,
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-04-18 10:36 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2012-02-03 13:52 [Bug c++/52108] New: declval() with incomplete type hidden_peak at mail dot ru
2012-02-03 14:37 ` [Bug c++/52108] " redi at gcc dot gnu.org
2012-04-18 9:10 ` abominable-snowman at yandex dot ru
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