But learning it, & understanding it takes 30 sec.

Instead of:
“What are these functions deleted?”

Why not:
“Oh, ok, these are explicit types!”

From: Jens Maurer via Std-Proposals<mailto:std-proposals_at_[hidden]>
Sent: 03 May 2022 12:22
To: Abdullah Qasim via Std-Proposals<mailto:std-proposals_at_[hidden]>
Cc: Jens Maurer<mailto:Jens.Maurer_at_[hidden]>
Subject: Re: [std-proposals] explicit keyword (new use)

On 03/05/2022 08.51, Abdullah Qasim via Std-Proposals wrote:
> But here is the thing:
>
>
>
> Why not make code simpler??

Because it requires everybody to learn a new wrinkle of
the language. That cost has to be weighed against the
perceived increase in simplicity.

Jens


> Why write multiple “= delete” functions, conscientiously tracking all conversions, when explicit inside functions is much simpler??
>
>
>
> Also, someone suggested explicit template parameters, like this:
>
>
>
> *template <explicit typename T>*
>
>
>
> Why not have consistence, & allow:
>
>
>
> *int func (explicit int x, int y)*
>
>
>
> as well?
>
>
>
> *From: *Jason McKesson via Std-Proposals <mailto:std-proposals_at_[hidden]>
> *Sent: *01 May 2022 22:07
> *To: *std-proposals_at_[hidden] <mailto:std-proposals_at_[hidden]>
> *Cc: *Jason McKesson <mailto:jmckesson_at_[hidden]>
> *Subject: *Re: [std-proposals] explicit keyword (new use)
>
>
>
> We have `= delete` for removing unwanted conversions. Indeed, you can
> basically force the use of `int` with:
>
> template<typename T>
> int func (int, T) = delete;
>
> Any call to `func` that doesn't pass an `int` as the second parameter
> will fail to compile. Even things convertible to `int` will not be
> used.
>
> If you want to allow more things to call it, you can only cull out
> floating-point types with this overload:
>
> int func(int, double) = delete;
>
> Calling func(5, 1) will work, but func(5, 3.4) or even func(5, 2.3f)
> will fail. This preserves the ability to call it with types
> convertible to `int` (but those which are convertible to `int` *and*
> floats will fail due to ambiguity).
>
> On Sun, May 1, 2022 at 3:57 AM Abdullah Qasim via Std-Proposals
> <std-proposals_at_[hidden]> wrote:
>>
>>
>>
>> int func (int var, explicit int select_menu)
>>
>> {
>>
>> /// ...
>>
>> }
>>
>>
>>
>> Why would I want user to put a double value in select_menu ???
>>
>>
>>
>> Also, why would I want to disallow a double in var ???
>>
>>
>>
>> The solution:
>>
>> Allow explicit in param list!!
>>
>>
>>
>> Not too hard to implement, either.
>>
>> --
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> --
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>
>
>
>

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