Flexible array, a la C99

[Christopher Benson-Manica]

The following program is, to the best of my knowledge, a conforming
C99 program:

#include <stdio.h>

typedef struct foo {
int whocares;
int bar[];
} foo;

int main() {
return( 0 );
}

The declaration of the zero-size array "bar" is not legal C++. Is
there a C++ construct that will do something similar, i.e., allow
something like the following declaration?

foo myFoo={ 1, {1,2,3} };

--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cyberspace.org | don't, I need to know. Flames welcome.

[Victor Bazarov]

Christopher Benson-Manica wrote:

The following program is, to the best of my knowledge, a conforming
C99 program:

#include <stdio.h>

typedef struct foo {
int whocares;
int bar[];
} foo;

int main() {
return( 0 );
}

The declaration of the zero-size array "bar" is not legal C++. Is
there a C++ construct that will do something similar, i.e., allow
something like the following declaration?

foo myFoo={ 1, {1,2,3} };

But of course!

struct foo {
int a;
int b[UINT_MAX];
};

:-)

V

[Christopher Benson-Manica]

Victor Bazarov <v.********@comacast.net> wrote:

struct foo {
int a;
int b[UINT_MAX];
}; :-)

I can think of ULONG_MAX reasons why I don't think I'm going to use
that, but the margin is too small to contain them :-)

--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cyberspace.org | don't, I need to know. Flames welcome.

[Shezan Baig]

Christopher Benson-Manica wrote:

The following program is, to the best of my knowledge, a conforming
C99 program:

#include <stdio.h>

typedef struct foo {
int whocares;
int bar[];
} foo;

int main() {
return( 0 );
}

The declaration of the zero-size array "bar" is not legal C++. Is
there a C++ construct that will do something similar, i.e., allow
something like the following declaration?

foo myFoo={ 1, {1,2,3} };

The best I can think of is:

template <int NUM_BARS>
struct foo {
int whocares;
int bar[NUM_BARS];
};
But this requires that you specify the size explicitly when you
construct the object:

foo<3> myFoo={ 1, {1,2,3} };
Hope this helps,
-shez-

[Victor Bazarov]

Shezan Baig wrote:

Christopher Benson-Manica wrote:

The following program is, to the best of my knowledge, a conforming
C99 program:

#include <stdio.h>

typedef struct foo {
int whocares;
int bar[];
} foo;

int main() {
return( 0 );
}

The declaration of the zero-size array "bar" is not legal C++. Is
there a C++ construct that will do something similar, i.e., allow
something like the following declaration?

foo myFoo={ 1, {1,2,3} };

The best I can think of is:

template <int NUM_BARS>
struct foo {
int whocares;
int bar[NUM_BARS];
};
But this requires that you specify the size explicitly when you
construct the object:

foo<3> myFoo={ 1, {1,2,3} };

The problem might be that different 'foo' instantiated with different
values are all different types. It's not that bad. You may specify
the number that is greater than the number of the initialisers in the
array.

V