gcc 3.3.3 compiles it just fine. g++ 3.3.3 doesnt. Since gcc 3.3.3 allows it, I hoped that g++ 3.3.3 would allow it too. N. --- corey taylor <corey.taylor@xxxxxxxxx> wrote: > Nitin, > > What compiler are you using with this code? > > As your link shows, the flexible arrays are only > legal in C99, and > their static initialization only legal through GCC > extensions. > > corey > > > On Sun, 13 Feb 2005 10:18:10 -0800 (PST), Nitin > Karkhanis > <nkarkhan@xxxxxxxxx> wrote: > > Thank you for your email. > > > > Flexible arrays are indeed legal. > > > http://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Zero-Length.html#Zero-Length > > (and it really is not a hack or a bad trick :), it > has > > been used for ages and I would be hard-pressed to > come > > up with an equally elegant solution to represent > > variable size arrays ) > > The trick of using the max array size is not > workable > > in embedded applications where memory is at a > premium. > > And then there is the static intialization > problem. > > > > e.g > > typedef struct { > > > > } a_t; > > > > I thought C++ is a superset of C and C code should > > compile in a C++ compiler (except for strict type > > checking) ..but guess not. > > > > N. > > > > --- Eljay Love-Jensen <eljay@xxxxxxxxx> wrote: > > > > > Hi Nitin, > > > > > > >Static initializations of a flexible array > works > > > with gcc but not with > > > g++ . is this by design? > > > > > > Yes, this is by design. C++ does not have > flexible > > > arrays (or what I've > > > heard called "stretchy arrays" or "stretchy > > > buffers"). C++ has STL > > > std::vector. > > > > > > The stretchy buffer is a bad trick -- it's not > > > portable, and may cause > > > certain optimizations to fail is a bad way. > > > > > > (I'm not sure if it is even legit C code. Maybe > it > > > is with C99. I dunno.) > > > > > > A suggestion is to do the reverse: specify the > > > structure with the array > > > given the maximum length, and allow allocations > of > > > less-than-maximum when > > > used off the heap. (There are caveats with this > > > approach as well.) > > > > > > struct flex_array_1000 > > > { > > > int A; > > > int Data[1000]; > > > }; > > > > > > Alternatively, you can use template structs to > > > provide more exacting > > > "hard-coded" arrays. > > > > > > template <int Count> > > > struct flex_array > > > { > > > int A; > > > int Data[Count]; > > > }; > > > > > > ...and you can have the struct derived from a > common > > > base class if you need > > > some sort of polymorphism. > > > > > > HTH, > > > --Eljay > > > > > > > > > > __________________________________ > > Do you Yahoo!? > > Take Yahoo! Mail with you! Get it on your mobile > phone. > > http://mobile.yahoo.com/maildemo > > > __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail
