Author: Heiner Marxen
Date: 08:11:37 06/07/04
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On June 07, 2004 at 10:46:28, Uri Blass wrote: >On June 07, 2004 at 10:40:09, Fabien Letouzey wrote: > >>On June 07, 2004 at 10:36:58, Vincent Diepeveen wrote: >> >>>On June 07, 2004 at 10:30:50, Fabien Letouzey wrote: >> >>>r = 1<<36; // works for good compilers not for the rest >> >>Hm, my understanding is that first "1<<36" should be calculated (so it's 0 if >>sizeof(int) <= 4) and *then* cast into r's type (oops, too late). >> >>Fabien. > >A smart compiler should understand that 1<<36 cannot mean 0 because in that case >the programmer has no reason to write it in that way. A smart programmer should understand that 1<<36 can mean 0 because in that case the C language does not impose a strict semantics. >The only logical meaning of 1<<36 is that it is a 64 bit number(espacially when >r is defined as a 64 bit number). No. I've used this kind of shifts to assert that the type "int" can contain a certain amount of bits. If the compiler would switch arbitrarily among types, I'd have a problem. C has a system of implicit casts, but it does not apply to this case. >Uri Cheers, Heiner
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