On 11/16/06, Casper.Dik at sun.com <Casper.Dik at sun.com> wrote:
>
> >Because argc is not an "integer constant expression". :-)
>
> We're talking about "variable length arrays"; clearly C++ does
> not support them.
>
> const int foo = X;
>
> is just a glorified #define giving you fixed size arrays.
#include <stdio.h>
#include <stdlib.h>
void foo(int x)
{
char arx[x];
(void) fprintf(stderr, "sizeof arx = %u\n", sizeof(arx));
}
int
main(int argc, char* argv[])
{
int sz;
if (argc != 2)
{
(void) fprintf(stderr, "nope\n");
return 1;
}
sz = atoi(argv[1]);
foo(sz);
foo(sz + 15);
foo(sz * 33);
return 0;
}
[steleman at redneck][~/tmp][11/16/2006 10:33:34][5845]>> c89 testval.c -o
testval
"testval.c", line 6: integral constant expression expected
c89: acomp failed for testval.c
[steleman at redneck][~/tmp][11/16/2006 10:33:42][5846]>> c99 testval.c -o
testval
[steleman at redneck][~/tmp][11/16/2006 10:33:50][5847]>> ./testval 7
sizeof arx = 7
sizeof arx = 22
sizeof arx = 231
[steleman at redneck][~/tmp][11/16/2006 10:34:02][5848]>>
--Stefan
--
Stefan Teleman
stefan.teleman at gmail.com
