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In-Reply-To: <6F41F6B1-E27B-4BF4-BDB0-66D63DA4F130@woofle.net>
Date: Wed, 5 Oct 2022 09:28:11 +0300
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To: Dusk <dusk@woofle.net>
Cc: PHP Internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Union type casts
From: zsidelnik@gmail.com (Eugene Sidelnyk)

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As I mentioned before, it would work the same alike way as if we called
function with such type-hint.

FMPOV, one of the most meaningful use-cases would be nullable casts (like
casting `?string` into `?float` for example).

Regards, Yevhen

On Wed, Oct 5, 2022, 8:41 AM Dusk <dusk@woofle.net> wrote:

> On Oct 4, 2022, at 21:46, Eugene Sidelnyk <zsidelnik@gmail.com> wrote:
> >    $foo = (int|float)$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:
>
>     $foo = \is_int($bar) ? $bar : (float) $bar;
>
> Or, even more concisely:
>
>     $foo = 0+$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.

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