[Bug c++/42983] [C++0x] Defaulted virtual destructor isn't virtual

[lavock at gmail dot com]

--- Comment #7 from lavock at gmail dot com  2010-02-08 13:49 ---
(In reply to comment #5)
> n3000 says "Only special member functions may be explicitly defaulted, and the
> implementation shall define them as if they had implicit definitions."
> 
> An implicit destructor is not virtual.
> 

An implicit definition does not mean an implicit declaration.

Moreover, the norm use sometimes this syntax.

There is a thread in comp.std.c++ about this.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42983

[Bug c++/42983] [C++0x] Defaulted virtual destructor isn't virtual

[lavock at gmail dot com]

--- Comment #17 from lavock at gmail dot com  2010-02-08 15:18 ---
(In reply to comment #16)
> Yes, but you're using an experimental implementation of an incomplete
> specification.  Using it for serious code would be foolish, so I tend to agree
> it's low priority

Yes, i agree with low priority, but maybe don't mark available for this
feature, since it seems to be partially available.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42983

[Bug c++/42983] New: [c++0x] Unvirtualzation of virtual destructor

[lavock at gmail dot com]

Hello,
The way to declare a inline virtual destructor within the class declaration
seems to unvirtualize it.
Trying the following code :

#include 

struct A {
  virtual ~A() = default;
};

struct B : A {
  virtual ~B() {
std::cout << "B destructor" << std::endl;
  }
};

int main() {
  B* b = new B;
  A * ptrA = *b;
  delete ptrA;
  return 0;
}

Nothing appear on standard output.


-- 
   Summary: [c++0x] Unvirtualzation of virtual destructor
   Product: gcc
   Version: 4.4.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
    ReportedBy: lavock at gmail dot com
 GCC build triplet: -486-linux-gnu
  GCC host triplet: -486-linux-gnu
GCC target triplet: -i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42983

[Bug c++/42983] [c++0x] Unvirtualization of virtual destructor

[lavock at gmail dot com]

--- Comment #2 from lavock at gmail dot com  2010-02-06 12:05 ---
(In reply to comment #1)
> Your testcase doesn't even compile:
> 
> 42983.C: In function ‘int main()’:
> 42983.C:15:15: error: cannot convert ‘B’ to ‘A*’ in initialization
> 

Sorry, my mistake, i've added an extra *...

#include 

struct A {
  virtual ~A() = default;
};

struct B : A {
  virtual ~B() {
std::cout << "B destructor" << std::endl;
  }
};

int main() {
  B* b = new B;
  A * ptrA = b;
  delete ptrA;
  return 0;
}


-- 

lavock at gmail dot com changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|INVALID |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42983