Re: encapsulating directory operations

On 30/05/2025 10:20, David Brown wrote:

On 29/05/2025 14:38, Richard Heathfield wrote:
 

This really is a very simple point, but perhaps a simple analogy will help to clarify it. You don't throw out your 3/4" just because you've bought a 19mm. There is room for both in the toolbox, and why write 3/4" on your new spanner? It /isn't/ a 3/4" spanner even though it's very like it, so why pretend otherwise?
>

 Your analogy does not cover C99 vs C90.

It does if we can construct a program that is legal C90 but not legal C99, which is easy enough, or (slightly harder but still not that hard) a program that is legal in both dialects but which gives different output under C99 than it does for C90.
$ cat c9099.c;gcc -W -Wall -ansi -pedantic -o c90 c9099.c;gcc -o c99 c9099.c;./c90;./c99
#include <stdio.h>
int main(void)
{
   int a = 42;
   int b = a //* comment */ 6;
   ;
   printf("Soln = %d\n", b);
   return 0;
}
Soln = 7
Soln = 42
Obviously it's a contrived example, but then examples pointing out the consequences of language differences invariably are.
--
Richard Heathfield
Email: rjh at cpax dot org dot uk
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