in reply to Range iterator outside integer range ... Why?

$ perl -e "print int ((1<<63)-512)"
9223372036854775296
$ perl -e "print int ((2**63)-512)"
9223372036854775808

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Re^2: Range iterator outside integer range ... Why?
by BrowserUk (Patriarch) on Jan 16, 2015 at 16:17 UTC

    So, if I'm interpreting your (rather terse) message correctly, because 2**63 is greater than a signed 64-bit int, it gets coersed into a double; before the subtraction is done.

    And because 63-bits of precision is greater than the 53 bits the double can retain, by the time the subtraction is done, the loss of precision causes the problem.

    In anycase, 1<<63-1 is a much nicer way of writing that constant. Thanks!

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      Or, as stated by oiskuu here, it's because 2**63 is implemented with pow, when 1<<63 actually works on integers.

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