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Date: Wed, 3 Apr 2019 11:17:59 -0500
Message-ID: <CAESVnVo-ysQ6f1BTgZsdCB6W1CLSj+paOFM0VwDNZs=cTPp=+w@mail.gmail.com>
To: Benjamin Morel <benjamin.morel@gmail.com>
Cc: PHP Internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] PHP_FLOAT_MIN is positive
From: pollita@php.net (Sara Golemon)

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On Wed, Apr 3, 2019 at 4:52 AM Benjamin Morel <benjamin.morel@gmail.com>
wrote:

> I just used PHP_FLOAT_MIN for the first time, and was surprised that it is
> the smallest **positive** number representable. Is this expected?
>
> This is unlike PHP_INT_MIN, which is the absolute smallest representable
> integer, and as such is negative:
>
> echo PHP_INT_MIN; // -9223372036854775808
> echo PHP_FLOAT_MIN; // 2.2250738585072E-308
>
> If it is intended, maybe the doc
> <https://www.php.net/manual/en/reserved.constants.php> should be clear
> about this, at the moment it is just:
>
> Smallest representable floating point number.
>
>
> Which is confusing IMO.
>
> Perhaps confusing, but not without precedent.  See the C++ definitions for
::min() and ::lowest() on
https://en.cppreference.com/w/cpp/types/numeric_limits.

std::numeric_limits<double>::min() is a positive value very near zero.
std::numeric::limits<double>::lowest() is a very large negative value.

-Sara

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