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* [Bug c++/15534] New: Fails to inherit types from base class
@ 2004-05-19 19:27 igodard at pacbell dot net
2004-05-19 19:42 ` [Bug c++/15534] " igodard at pacbell dot net
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: igodard at pacbell dot net @ 2004-05-19 19:27 UTC (permalink / raw)
To: gcc-bugs
In the source at the point of the first error messages:
typedef
typename std::allocator<T>::size_type st1;
typedef
typename size_type st;
typedef
size_type st2;
the first typedef works but the second two do not even though the class is derived from std::allocator<T>. In simple cases, e.g.:class A{
public:
typedef
int B;
};
class C : public A {
public:
B b;
};
the derived class can inherit the types of the base class, but not here. Sticking in a "typename" doesn't help.
--
Summary: Fails to inherit types from base class
Product: gcc
Version: 3.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: igodard at pacbell dot net
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
@ 2004-05-19 19:42 ` igodard at pacbell dot net
2004-05-19 19:47 ` igodard at pacbell dot net
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: igodard at pacbell dot net @ 2004-05-19 19:42 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From igodard at pacbell dot net 2004-05-19 03:04 -------
Created an attachment (id=6334)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6334&action=view)
Compiler output (-v -save-temps)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
2004-05-19 19:42 ` [Bug c++/15534] " igodard at pacbell dot net
@ 2004-05-19 19:47 ` igodard at pacbell dot net
2004-05-19 20:22 ` pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: igodard at pacbell dot net @ 2004-05-19 19:47 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From igodard at pacbell dot net 2004-05-19 03:06 -------
Created an attachment (id=6335)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6335&action=view)
Source code (-save-temps)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
2004-05-19 19:42 ` [Bug c++/15534] " igodard at pacbell dot net
2004-05-19 19:47 ` igodard at pacbell dot net
@ 2004-05-19 20:22 ` pinskia at gcc dot gnu dot org
2004-05-19 23:47 ` igodard at pacbell dot net
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-19 20:22 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-05-19 03:12 -------
This is equivent to:
template <class T> class A
{
typedef int t;
};
template <class T> class B: A<T>
{
typedef t t1;
};
Which is invalid as t is not dependent so it needs to be declare not in the subclasses.
The fix would be to declare t1 as "typedef A<T>::t t1;"
Also one the mainline I get the following note:
pr15534.ii:31253: error: `size_type' does not name a type
pr15534.ii:31253: note: (perhaps `typename std::allocator<_CharT>::size_type' was intended)
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
` (2 preceding siblings ...)
2004-05-19 20:22 ` pinskia at gcc dot gnu dot org
@ 2004-05-19 23:47 ` igodard at pacbell dot net
2004-05-20 0:59 ` pinskia at gcc dot gnu dot org
2004-05-20 13:37 ` bangerth at dealii dot org
5 siblings, 0 replies; 7+ messages in thread
From: igodard at pacbell dot net @ 2004-05-19 23:47 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From igodard at pacbell dot net 2004-05-19 09:30 -------
Comment three says the original example was invalid:
"Which is invalid as t is not dependent so it needs to be declare not in the subclasses". So here is a different example where "t" *is* dependent, and it fails too.
template <class T> class A
{
typedef T* t;
};
template <class T> class B: A<T>
{
typedef t t1;
};
or am I not understanding what you mean by dependent?
g++3.4.0 gives:
foo.cc:8: error: `t' does not name a type
foo.cc:8: error: (perhaps `typename A<T>::t' was intended)
Ivan
--
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
` (3 preceding siblings ...)
2004-05-19 23:47 ` igodard at pacbell dot net
@ 2004-05-20 0:59 ` pinskia at gcc dot gnu dot org
2004-05-20 13:37 ` bangerth at dealii dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-20 0:59 UTC (permalink / raw)
To: gcc-bugs
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------- Additional Comments From pinskia at gcc dot gnu dot org 2004-05-19 11:16 -------
You misunderstand.
Type-dependent expressions (From 14.6.2.2 P3):
Anid-expressionis type-dependent if it contains:
an identifier that was declared with a dependent type,
a template-id that is dependent,
a conversion-function-id that specifies a dependent type,
a nested-name-specifier that contains a class-name that names a dependent type.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/15534] Fails to inherit types from base class
2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
` (4 preceding siblings ...)
2004-05-20 0:59 ` pinskia at gcc dot gnu dot org
@ 2004-05-20 13:37 ` bangerth at dealii dot org
5 siblings, 0 replies; 7+ messages in thread
From: bangerth at dealii dot org @ 2004-05-20 13:37 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From bangerth at dealii dot org 2004-05-19 13:42 -------
In your example,
------
template <class T> class B: A<T>
{
typedef t t1;
};
------
you reference the name 't'. Since 't' does not depend on the template
argument 'T', it is non-dependent and needs to be looked up at the
time of declaration of the template. However, since name lookup does
not look into template dependent base classes such as A<T> it doesn't
find anything. The solution is to make sure that 't' is qualified as
dependent, for example by writing 'typename A<T>::t'.
This is really no different than all the other name lookup things that
we believe are well-documented in the non-bugs and changes-in-3.4 sections
of our web pages. Please review these if you are unsure.
W.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15534
^ permalink raw reply [flat|nested] 7+ messages in thread
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2004-05-19 19:27 [Bug c++/15534] New: Fails to inherit types from base class igodard at pacbell dot net
2004-05-19 19:42 ` [Bug c++/15534] " igodard at pacbell dot net
2004-05-19 19:47 ` igodard at pacbell dot net
2004-05-19 20:22 ` pinskia at gcc dot gnu dot org
2004-05-19 23:47 ` igodard at pacbell dot net
2004-05-20 0:59 ` pinskia at gcc dot gnu dot org
2004-05-20 13:37 ` bangerth at dealii dot org
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