The actual requirements:
•That you 'use integer'
•That the size of your perl's integer is 4 bytes (check perl -V:ivsize) or that you use & 0xFFFF_FFFF

I think there's at least one more condition, namely: Do not assign a value that's greater than UINT_MAX.

I don't know what others expect to happen when, having chosen to 'use integer', one assigns (to a perl scalar) a value that is greater than UINT_MAX, but the result is one that I do not expect.
This is behaviour that I do expect when ivsize is 4: 
C:\> perl -Minteger -wle "$x = 4294967295 + 3;print $x;"
2

[download]
And I expect the same output when I do: 
C:\> perl -Minteger -wle "$x = 4294967298;print $x;"
4294967298

[download]
Alas, such handling of this corner case leaves me feeling uneasy about using the integer pragma at all.

How many other surprises (or traps for the unwary) are to be found in the finer details of this pragma's behaviour ?

Cheers,
Rob

In reply to Re^3: perl arithmetic is killing me! HELP! by syphilis
in thread perl arithmetic is killing me! HELP! by harangzsolt33

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