... the C-style loop allows it only when I use bignum (but not Math::BigInt)

You can use the C-style loop with Math::BigInt, but you just have to create $x in a slightly different way - eg: 
use warnings;
use strict;
use feature 'say';
use Math::BigInt;

my $x = Math::BigInt->new(1);
$x <<= 1024;

for(my $i = $x; $i <= $x + 2; $i++) {
  say $i;
  }

[download]
The C-style loop works with both bignum and Math::BigInt because it makes use of operators that are overloaded. Unfortunately, the '..' operator is not currently overloaded, and that's why the second loop fails.

Cheers,
Rob

In reply to Re: big integers forcing me to be a C programmer: "range iterator outside integer range" by syphilis
in thread big integers forcing me to be a C programmer: "range iterator outside integer range" by Boldra

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