std::move<T&&>(o) doesn't work on explicit conversions and doesn't work on
rvalue qualified conversions which is the whole point
explicit operator T&&()&& is the conversion I want to be used

Tymi.

On Wed, 4 Jun 2025, 13:32 Jonathan Wakely, <cxx_at_[hidden]> wrote:

>
>
> On Wed, 4 Jun 2025, 11:56 Tymi, <tymi.cpp_at_[hidden]> wrote:
>
>> The U& is a typo, U&& would be the correct one. Wrote that one on the fly
>>
>
> Then it's broken for lvalues, you need to use remove_reference_t<U>&& in
> the body
>
> Please actually implement this and test it properly before proposing it
> here, where lots of people spend time on it.
>
>
>
>
>
>> Tymi.
>>
>> On Wed, 4 Jun 2025, 12:54 Tymi, <tymi.cpp_at_[hidden]> wrote:
>>
>>> Same reason why std::move exists
>>> Why do we have std::move? Why not just use static_cast<T&&>(value)?
>>>
>>> Tymi.
>>>
>>> On Wed, 4 Jun 2025, 12:19 Jonathan Wakely, <cxx_at_[hidden]> wrote:
>>>
>>>>
>>>>
>>>> On Wed, 4 Jun 2025, 10:14 Tymi, <tymi.cpp_at_[hidden]> wrote:
>>>>
>>>>> "moving" meaning "using std::move" meaning casting to an rvalue
>>>>> reference, let's not point such things out when we know what we are talking
>>>>> about :/
>>>>>
>>>>>
>>>>> > I don't think your std:: expected example works, it didn't have a
>>>>> conversion operator. What you want is just std:: move(*exp) or
>>>>> *std::move(exp).
>>>>>
>>>>> My std::expected example does not currently work, but std::move_as
>>>>> opens a possibility for std::expected to implement such a conversion.
>>>>> std::move(*myExpected) works, but std::move_as<Value>(myExpected) seems
>>>>> cleaner to me.
>>>>>
>>>>
>>>> It seems more verbose and completely unnecessary when you can already
>>>> achieve the same thing.
>>>>
>>>> Not being convertible to its result is an intentional design choice for
>>>> expected (and for optional) so changing that to enable your new feature
>>>> seems like a bad trade off.
>>>>
>>>> > And your string example works with just
>>>>> static_cast<std::string&&>(obj).
>>>>>
>>>>> And no, static_cast<std::string&&>(obj) does not work.
>>>>>
>>>>
>>>> Oh right, your conversion is && qualified. So
>>>> static_cast<string&&>(std::move(obj))
>>>>
>>>> I still see no need to introduce a new feature to do this.
>>>>
>>>>
>>>>
>>>> On 04.06.2025 11:08, Jonathan Wakely wrote:
>>>>>
>>>>>
>>>>>
>>>>> On Wed, 4 Jun 2025, 09:03 Tymi via Std-Proposals, <
>>>>> std-proposals_at_[hidden]> wrote:
>>>>>
>>>>>> I find the move_as example more intuitive and generally "safer". Also
>>>>>> my first thought was that std::string(std::move(c)) copied c._value and
>>>>>> created a new object out of it, instead of just moving c._value.
>>>>>>
>>>>>
>>>>> You seem to be saying "moving" when you mean "casting to rvalue
>>>>> reference", which is not moving.
>>>>>
>>>>>
>>>>> I don't think your std:: expected example works, it didn't have a
>>>>> conversion operator. What you want is just std:: move(*exp) or
>>>>> *std::move(exp).
>>>>>
>>>>> And your string example works with just
>>>>> static_cast<std::string&&>(obj).
>>>>>
>>>>> So I think the existing solutions are fine.
>>>>>
>>>>>
>>>>>