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Date: Fri, 13 Mar 2015 22:31:00 -0600
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To: Rasmus Lerdorf <rasmus@lerdorf.com>
Cc: Zeev Suraski <zeev@zend.com>, Dmitry Stogov <dmitry@zend.com>, 
	"francois@php.net" <francois@php.net>, PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] [VOTE][RFC] Coercive Scalar Type Hints
From: levim@php.net (Levi Morrison)

On Fri, Mar 13, 2015 at 8:50 PM, Rasmus Lerdorf <rasmus@lerdorf.com> wrote:
> On Mar 14, 2015, at 13:37, Levi Morrison <levim@php.net> wrote:
>> It seems that `float -> bool` is always disallowed. If I am correct
>> `int -> bool` is permitted for all values (not just 0 and 1), which
>> means that floats which can be converted to integers without dataloss
>> should also be permitted to be booleans. If a specific float can be
>> converted to an int, and all ints can be converted to booleans, then
>> the transitive property should hold for that float to a bool.
>
> The problem there is what does "without dataloss" mean? At which precision do you consider there to be no dataloss?

Ah, I reread part of the RFC. It appears `float -> int` is unchanged
from current. This only confuses me more, though. If int -> float is
permitted, and float -> int is permitted, I do not understand why
float -> bool is not permitted.

Can someone clarify this?