[Bug c++/13484] Addition of -fenable-msvc-relaxations option

["s_gccbugzilla at nedprod dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From s_gccbugzilla at nedprod dot com  2003-12-24 18:30 -------
Firstly to answer pinskia's point, from my understanding const temporaries are 
not specified absolutely by the ISO C++ standard - it appears to be one of 
interpretation (I don't have an up to date copy myself to check though). It's 
also a very sore bone of contention as searching google shows because a LOT of 
MSVC based code just won't compile on GCC and all the GCC people say "tough, 
that's the standard".

I personally feel that's particularly unhelpful for two reasons: (i) This 
position is a particular *interpretation* of the standard and (ii) like it or 
not, a hell of a lot of code is written for MSVC first - compilers are /tools/ 
first before all else. When Symbian and GCC-XML based development relies so 
heavily on MSVC and GCC working similarly, it is a sign of the great strength of 
the open source philosophy that one can say "yes, we can interoperate". 
Especially if it's like five lines of extra code in G++ with no maintainence 
cost!

To answer giovannibajo, here's something from my own code (as small as possible)
:

class dllHandle
{
   dllHandle(); // private constructor as dllOpen() is a friend
public:
   dllHandle(dllHandle &other); // move constructor
};

static dllHandle FXProcess::dllOpen(const char *dllname);
static void FXProcess::dllResolve(const dllHandle &h, const char *symbol);
static void FXProcess::dllFree(dllHandle &h);

Here we have an ideal case of why move constructors are so useful. Yes, the ISO 
C++ standard will get them eventually. However before then lots of MSVC people 
are using non-const copy constructors in their code to implement a move 
constructor.

Now try porting that to GCC. Answer is you can't unless you make the contents of 
dllHandle all mutable which defeats the point of const.

As I said before, for such a small *optional* addition to GCC you greatly 
improve its interoperability with MSVC. Which is the world's most popular C++ 
compiler. Which has substantial benefits for Symbian development as well as 
GCC-XML.

Cheers,
Niall


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|WONTFIX                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13484