Re:Pitfalls in C and C++: Unsigned Types (2011)
by pslam on Wednesday September 25, 2013 @02:57PM
(#6446545)
buf[4294967295] is perfectly valid and expected on platforms where size_t is 64 bits and int is 32 bits. buf[-1] is almost always a bug, and would be useful to default (with overrides) as such.
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Re:Pitfalls in C and C++: Unsigned Types (2011)
by dllthomas on Wednesday September 25, 2013 @03:13PM
(#6446644)
if buf[4295967295] is valid, then you should almost certainly be indexing with something bigger than 32 bits, and the max of your index is again likely to be invalid (and, as I've mentioned elsewhere, more usefully invalid than -1).
Re:Pitfalls in C and C++: Unsigned Types (2011)
by dllthomas on Thursday September 26, 2013 @03:14AM
(#6449349)
On reflection, using something larger doesn't help, since if sizeof(void*) == sizeof(i) then a[(__typeof(i))-1] will almost certainly refer to the same address whether i is signed or unsigned.