Messages in this thread | | | Date | Wed, 9 Nov 2005 15:40:02 -0800 (PST) | From | Vadim Lobanov <> | Subject | Re: typedefs and structs |
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On Thu, 10 Nov 2005, Andreas Schwab wrote:
> Vadim Lobanov <vlobanov@speakeasy.net> writes: > > > However, if the code is as follows: > > void foo (void) { > > int myvar = 0; > > printf("%d\n", myvar); > > bar(&myvar); > > printf("%d\n", myvar); > > } > > If bar is declared in _another_ file as > > void bar (const int * var); > > then I think the compiler can validly cache the value of 'myvar' for the > > second printf without re-reading it. Correct/incorrect? > > Incorrect. bar() may cast away const. In C const does not mean readonly.
In that case, I stand corrected.
Is there any real reason to apply const to pointer targets, aside from giving yourself a warning in the case you try to write the pointer target directly? Seems to be a missed opportunity for optimizations where the coder designates that it's okay to do so.
> Andreas. > > -- > Andreas Schwab, SuSE Labs, schwab@suse.de > SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany > PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 > "And now for something completely different." >
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