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my $x = ( 1 << 54 ) | 1; say $x; # 18014398509481985 $x = unpack 'F', pack 'F', $x; $x = unpack 'J', pack 'J', $x; say $x; # 18014398509481984

To support negative numbers, use I instead of J for negative numbers.


The following is a little bit truer to a cast, but it's far more complicated, far more fragile (can fail for overloaded and magical vars), and technically uses XS:

use strict; use warnings; use feature qw( say ); use B qw( svref_2object ); my $x = ( 1 << 54 ) | 1; say $x; # 18014398509481985 # Add the value as an NV to the scalar. { no warnings qw( void ); log $x; } # Make it so the scalar contains just an NV. $x = svref_2object(\$x)->NV; # Add the value as an IV or UV to the scalar. { no warnings qw( void ); $x | 1; } # Make it so the scalar contains just an IV or UV. $x = svref_2object(\$x)->int_value; say $x; # 18014398509481984

In reply to Re^3: Detecting whether UV fits into an NV by ikegami
in thread Detecting whether UV fits into an NV by syphilis

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