C2 forum

General Category => Ideas => Topic started by: acbaile on January 21, 2019, 05:17:26 PM

Title: deleted
Post by: acbaile on January 21, 2019, 05:17:26 PM

deleted

Title: Re: Unnatural behavior in C type cast - (uint64)(int32)
Post by: chqrlie on January 21, 2019, 11:36:34 PM

I agree that the behavior uint64 var3 = (uint64)(int64)var0; is somewhat unnatural, but converting a negative value as an unsigned value is bound to cause surprising results. Your solution is just as surprising: uint64 var4 = (uint64)(uint32)var0; has the disadvantage that converting the resulting value back to a signed type int64 does not produce the original value, whereas the C semantics do ensure that.

In other words (int64)var3 == var0 for all values of var0, but (int64)var4 == var0 only holds for positive values of var0.

I rest my case.