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In-Reply-To: <CAM0CcxgCT=M++9fTosG8FzuCKn=v8VQykRQY1E8_BzT=k_rk4w@mail.gmail.com>
Date: Tue, 4 Oct 2022 22:41:48 -0700
Cc: PHP Internals <internals@lists.php.net>
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To: Eugene Sidelnyk <zsidelnik@gmail.com>
Subject: Re: [PHP-DEV] Union type casts
From: dusk@woofle.net (Dusk)

On Oct 4, 2022, at 21:46, Eugene Sidelnyk <zsidelnik@gmail.com> wrote:
>    $foo =3D (int|float)$bar;

As written, I wouldn't know what to expect this to do with a string =
value -- would it cast it to int or float?

Based on the behavior of your second example, the answer appears to be =
"float", so this syntax seems to be equivalent to:

    $foo =3D \is_int($bar) ? $bar : (float) $bar;

Or, even more concisely:

    $foo =3D 0+$bar;

I'd be even less sure what to expect when casting to other union types. =
What would the expected result of casting a string to =
(bool|array|object) be, for example? I'm not sure there are many =
meaningful operations which could be constructed here.=