Hello Thomas!

22 Jul 96 10:56, Thomas Seeling wrote to Daniel Lynes:

 TS> void foo(int *x) {
 TS>   int z;

 TS> /* this is ok, but senseless */
 TS>   *x++;

test.c(5): Warning! W302: Expression is only useful for its side effects

 TS> /* this is illegal, since x does not contain a "legal" pointer */
 TS>   z=*x;

However, the compiler does not spit out an error for this; nor, do I see why it
should.  Basically you're assigning the value contained in the pointer x, to
the variable, z.  Why is this illegal?  Did you try compiling it?

When the *x++; is commented out, z=1.  When the *x++; is not commented out,
z=71565.  However, z I don't believe is guaranteed to be any specific number,
lending to the fact that *x++; is only useful for its side effects.  i.e.  its
behaviour is unpredictable.

Daniel

internet:  dbl{at}eznet.ca

... Children have more need of models than of critics.

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