[Python-Dev] Caching float(0.0)

["Martin v. Löwis"]

Alastair Houghton schrieb:
> On 3 Oct 2006, at 17:47, James Y Knight wrote:
> 
>> On Oct 3, 2006, at 8:30 AM, Martin v. Löwis wrote:
>>> As Michael Hudson observed, this is difficult to implement, though:
>>> You can't distinguish between -0.0 and +0.0 easily, yet you should.
>>
>> Of course you can. It's absolutely trivial. The only part that's even
>> *the least bit* sketchy in this is assuming that a double is 64 bits.
>> Practically speaking, that is true on all architectures I know of,
> 
> How about doing 1.0 / x, where x is the number you want to test?  

This is a bad idea. It may cause a trap, leading to program termination.

Regards,
Martin