On 19/04/2022 10:37, Edward Catmur wrote:
> On Tue, 19 Apr 2022 at 03:22, <language.lawyer@gmail.com> wrote:
>
>> On 18/04/2022 23:23, Edward Catmur wrote:
>>> On Mon, 18 Apr 2022 at 21:13, <language.lawyer@gmail.com> wrote:
>>>
>>>> On 18/04/2022 22:57, Edward Catmur wrote:
>>>>> I suppose that paragraph <
>> https://eel.is/c++draft/expr.call#7.sentence-4>
>>>> (and
>>>>> the following Note) should be struck entirely.
>>>> I'd say then we will not know which object [expr.prim.this]/1 speaks
>> about
>>>> («The keyword `this` names a pointer to the object for which an implicit
>>>> object member function is invoked»)
>>>>
>>>
>>> "the object for which an implicit object member function is invoked"
>> seems
>>> clear enough; per [expr.call]/2 it's the object expression on the LHS of
>>> the postfix expression (before the '.', '->', '.*' or '->*').
>>
>> If it is a base-class function, the object is the corresponding base class
>> subobject, isn't it?
>>
>
> Yes, but that's a problem with [expr.prim.this]/1; you can't have a pointer
> of base type pointing to an object of derived type. So that subclause is
> also defective, and should have appended ", or to its base class subobject,
> as appropriate".

I don't understand where the defect is.
When «the object for which function is invoked» is a base class subobject (and it is pointed to by `this`), there is no discrepancy between the type of `this` and the object's type.
«The object for which function is invoked» does not have to be «the result of the object expression».

> As for [expr.call]/7, there's no need to specify *how* the implementation
> is expected to come up with the value of the `this` pointer (although it
> could be a Note).

When you say that [expc.call]/2 defines the object for which the function is invoked, do you mean «the call is as a member of the class object referred to by the object expression»?