[Bug libstdc++/29286] [4.0/4.1/4.2/4.3 Regression] placement new does not change the dynamic type as it should

["gdr at integrable-solutions dot net" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #24 from gdr at integrable-solutions dot net  2006-10-24 06:53 -------
Subject: Re:  [4.0/4.1/4.2 Regression] placement new does not change the
dynamic type as it should

"mark at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org> writes:

| ------- Comment #22 from mark at codesourcery dot com  2006-10-04 05:39
-------
| Subject: Re:  [4.0/4.1/4.2 Regression] placement new
|  does not change the dynamic type as it should
| 
| ian at airs dot com wrote:
| > ------- Comment #21 from ian at airs dot com  2006-10-03 23:44 -------
| > In C a general allocation function should work with a char array.  A
specific
| > allocation function should use a union.  I don't think there are many
existing
| > exceptions to these guidelines.
| 
| > So I don't see a serious problem in C either.  Am I missing something/
| 
| I think there are two remaining issues:
| 
|    int i;
|    *(float*)(&i) = 7.0;
| 
| IIUC, Mike's position is that this is valid -- and that, in fact, after 
| this point "i" can no longer be accessed as an int.  Do you agree?  

I don't see how that code is supported by the paragraphs quoted by Mike.
There was a recent discussion (at most two weeks ago) on the C++
standard reflector -core about similar topic.  I do agree with Mark
that the proper way to resolve this is to go to the C++ committee.
It would be incredible that C++ was less type-strict than C.

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29286