Re: [boost] [Hana/Fit] about constexpr/noexcept on equivalent functions to std::overload

Subject: Re: [boost] [Hana/Fit] about constexpr/noexcept on equivalent functions to std::overload
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2016-07-07 12:57:47

Le 04/07/2016 à 23:10, Louis Dionne a écrit :
> Vicente J. Botet Escriba <vicente.botet <at> wanadoo.fr> writes:
>
>> Hi,
>>
>> On the C++ standard meating in Oulu, we decided to make the
>> std::overload function constexpr and conditionaly noexcept and ensure
>> that the overloaded functions shall be constexpr if the stored finctions
>> are.
>>
>> I don't find in the reference documentation of Hana and Fit any
>> reference of whether the overloaded functions preserve constexpr or not.
> The usual rule that's valid across Hana is that whenever the inputs are
> constexpr, the outputs are constexpr too. Hence, when you use `hana::overload`
> with constexpr functions, the result will be constexpr. And if these functions
> can be called in a constant expression, then so does the resulting
> `hana::overload`.
>
>

There is no problem for function objects.

Louis, I don't remember, does Hana overload accepts pointer to member or 
non-member functions?

Vicente