Hey, all. What'd I goof up here? 
use bignum;

$foo = 12345.6789;
$bar = $foo->copy()->bfround(0);
$baz = $foo - $bar;
print "what's wrong here? $baz\n";

$byhand = 12345.6789 - 12345;
print "as expected $byhand\n";

[download]
... which does this: 
what's wrong here? 0
as expected 0.6789

[download]
So the subtraction is getting zero, where I expected roughly 0.6789 also. And yes, I get the same thing if i use $baz = $foo->bsub($bar).
Any hints appreciated. Thanks!

Update - Thanks for the welcome; I've been lurking and annonning for years so it was prolly time. It was indeed a contamination of precision. When doing the bfround(0) you can Dumper the result and see it picked up a p=0 member, which got carried along after that. The bfround(0)->bfround(-5) solution works but I need to rtfm a couple more times to get my head around it. The problem I was trying to solve was merely, "what's the distance from this float to the nearest integer, wherever that is"

In reply to bignum frustration by not_japh

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