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Date: Wed, 23 Jan 2019 15:43:20 +0100
Cc: Arvids Godjuks <arvids.godjuks@gmail.com>,
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To: Girgias <george.banyard@gmail.com>
Subject: Re: [PHP-DEV] Deprecation ideas for PHP 8
From: claude.pache@gmail.com (Claude Pache)



> Le 23 janv. 2019 =C3=A0 14:19, Girgias <george.banyard@gmail.com> a =
=C3=A9crit :
>=20
>=20
>=20
> On Wed, 23 Jan 2019 at 09:19, Claude Pache <claude.pache@gmail.com> =
wrote:
>=20
>>=20
>>>  - settype
>>=20
>> AFAICS, there is no easy replacement for settype(). If the second =
argument
>> is a string literal, you can use type coercion + assignment at the =
price of
>> duplicating the occurrence of the first argument. If the second =
argument is
>> not known at compile time, you have to resort to a switch statement =
or
>> something similar.
>>=20
>=20
> I did not consider that someone might want to set the type of a =
variable at
> runtime because
> I can not see any pratical usages for that, imho you change a variable =
type
> into another one
> because you want to work with that specific type. But it basically =
boils
> down to the same issue
> as with gettype that without it you need to do a switch statement to =
get
> something similar.
>=20
>=20

So, since you didn=E2=80=99t see, here are some practical usages of =
settype():

<?php
function foo($bar) {
    // $bar is supposed to be either a string, or a list of strings
    settype($bar, 'array');
    // ...
}

function qux($id) {
     if (!(is_int($id) || is_string($id) && ctype_digit($id)))
        throw new \TypeError;
    settype($id, 'int');
    // ...
}

class Foo implements SeekableIterator {
    function seek(/* int */ $position): void {
        // NOTE: we cannot use int typehint here, because PHP7.1 =
requires mixed
        settype($position, 'int');
        // ...
    }
}
?>

Here are a usage of settype() with a non-constant second parameter: =
Define a utility function that cast a value to a given type when it is =
not null:

<?php
function cast_opt($val, $type) {
    if ($val !=3D=3D null)
        settype($val, $type);
    return $val;
}

$foo =3D cast_opt($bar, 'int') // equivalent to: $foo =3D $bar =3D=3D=3D =
null ? null : (int) $bar;
?>

Sure, one can avoid settype() and do it the complicated way, but why? =
What is the issue with settype(), so that you want to deprecate it?

=E2=80=94Claude