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Re: const issues
Hi Jason,
your code isn't valid C. A global variable can only be initialized
with a compile-time constant, and a const variable isn't a
compile-time constant in C. Compare with the following program:
#include <stdlib.h>
const int a = 42;
const int b = a; // Error
int main()
{
return 0;
}
See e.g. http://c-faq.com/ansi/constasconst.html
By contrast, in C++ a global const integral variable is a compile-time
constant, and you can use it as an initializer.
Dario
2008/2/29, Jason Pepas <jasonpepas@gmail.com>:
> this compiles as expected:
>
>
> #include <stdlib.h>
>
> int main()
> {
> const int a = 42;
> const int * const b = &a;
> const int * const c = b;
>
> return EXIT_SUCCESS;
> }
>
>
> but moving the variables outside of the function causes gcc to die
> with "error: initializer element is not constant" on line 5 (the "c =
> b" line):
>
>
> #include <stdlib.h>
>
> const int a = 42;
> const int * const b = &a;
> const int * const c = b;
>
> int main()
> {
> return EXIT_SUCCESS;
> }
>
>
> As best as I can tell, the error is a lie: I can't make that any more
> const than it already is.
>
> ideas?
>
>
> -jason pepas
>