At Thu, 15 Oct 2009 06:09:40 -0700 (PDT) =?ISO-8859-1?Q?Nordl=F6w?=
<per.nord...@gmail.com> wrote:
>
> GCC's C Extensions gives us zero and variable length arrays.
>
> Is it possible to get variable length arrays as members ("by-value")
> in C++ classes aswell, something like:
>
> class string255
> {
> private:
> char size;
> char val[size];
> }:
>
> I guess it all boils downto how C++ allocates a class.
>
> Can we give gcc hints about this somehow?
That is one of the things that what constructors and static members are
for.
You can't define a member array with another member as the size, but you
can do this:
class string255
{
private:
char size;
char *val;
char dummy;
public:
string255(int _size) {
assert(_size > 0 && _size < 256);
val = new char[_size];
size = _size;
}
~string255() {
if (val != null) delete val[];
}
char& operator [] (i) {
if (i >= 0 && i < size) return val[i];
else return dummy;
}
};
This pretty much implements what you want I believe. i suspect you will
want to add a copy constructor and an assignment operator method, but I
will leave them as a homework assignment :-). If you want something
'more automagical' there is the STL or maybe you want to use a dufferent
OO language altogether (Tcl+SNIT maybe).
>
> /Nordl=F6w
>
>
--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows
hel...@deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/
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