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On Wednesday 29 October 2008 00:55:42 Jorge Peixoto de Morais Neto wrote: |
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> >> I mean to really know C, |
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> >> that is, read a rigorous book such as "C: A Reference Manual" and be |
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> >> able to write portable programs with well-defined behavior. Speaking |
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> >> of well-defined behavior, do you know what happens when you cast a |
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> >> float to an int, and the float is too big to fit into the int? |
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> > |
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> > Did oyu try it yourself and see? |
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> |
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> The point is that the behavior in this situation is "undefined". It |
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> might do anything. Programming in C is different than programming in |
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> Python. |
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Most likely the compiler will try to treat the float as an int and use the |
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first 4 bytes of the float, ignoring the rest. |
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This is insane though. I cannot think of any reason why one would ever want to |
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treat the first 32 bits of a float as an int. It's not like you are casting a |
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long to an int which can make sense - just discard the high bits. |
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I reckon the standard would say this is undefined. Most compiler would bomb |
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out with a compile error but give you an obscure flag to proceed anyway. If |
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you want to commit suicide, C is quite happy to pass you the pills as long s |
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you ask nicely |
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-- |
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alan dot mckinnon at gmail dot com |
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