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Subject: Re: [std-proposals] Proposal - Allow '.' operator to work on pointers (again sortof)
From: J Decker (d3ck0r_at_[hidden])
Date: 2020-03-04 21:15:24


On Wed, Mar 4, 2020 at 7:09 PM J Decker <d3ck0r_at_[hidden]> wrote:

>
>
> On Wed, Mar 4, 2020 at 5:11 PM Andrey Semashev via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
>
>> On 2020-03-05 03:44, J Decker via Std-Proposals wrote:
>> > Reformatted this to resemble standard proposal
>> >
>> > https://gist.github.com/d3x0r/f496d0032476ed8b6f980f7ed31280da
>> > It fails to be ' The proposal may be in PDF, HTML, or plain text
>> formats. '
>> >
>> > TL;DR
>> >
>> > C Standard section 6.5.2.3 Structure and union members
>> >
>> > add text in [ ]
>> >
>> > 1- The first operand of the . operator shall have a qualified or
>> > unqualified structure or union type or [‘‘pointer to qualified or
>> > unqualified structure’’ or ‘‘pointer to qualified or unqualified
>> > union’’,] and the second operand shall name a member of that type.
>> >
>> > C++ Standard section 8.5.1.5 Class member access
>> >
>> > add: if the first expression of (dot) is a pointer [to an object], then
>> > E1.E2 is converted to (*(E1)).E2 .
>>
>> I don't find your motivation compelling. The other languages you refer
>> to (which ones? Java? JavaScript?) likely don't have the concept of a
>> pointer and thus don't need a separate operator. You've been shown
>> examples where having operators . and -> behave the same would break
>> code. Special casing the proposal just for raw pointers is breaking
>> consistency. So no, just no.
>>
>
> I'm sorry I have seen 0 examples where they conflict in meaning and don't
> continue to work the same way.
> This maybe isn't as compelling for C++ which continues to have to use ->
>
> I have noted the complaint and will consider improving that.
> rust, c#, go, kotlin, dart, typescript, ruby, python, swift (repurposes ->
> as a type)....
>
> I don't know any that don't wait... https://cucumber.io/ this is a
> testing framework
>
> >
>
(Sorry that image was cut, replace with text)

> Feature: Guess the word
>
> # The first example has two steps
> Scenario: Maker starts a game
> When the Maker starts a game
> Then the Maker waits for a Breaker to join
>
> # The second example has three steps
> Scenario: Breaker joins a game
> Given the Maker has started a game with the word "silky"
> When the Breaker joins the Maker's game
>
> Then the Breaker must guess a word with 5 characters
>
>

> C# has value type 'struct' which are values and are accessed with '.'
> where a 'class' is always a reference type, and is always dereferencing a
> pointer.
>
> J
>
> --
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>> Std-Proposals_at_[hidden]
>> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
>>
>



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