Re: Tagging the minimum C++ standard level for Boost libs

From: Alexander Grund (alexander.grund_at_[hidden])
Date: 2020-12-16 08:52:17

>> I would not treat a missing cxxstd as "C++03" because that makes the 
>> proposal mostly useless: Your goal was to tell end users whether they 
>> can use the library given their std level. Now you treat libraries 
>> with missing information as "compatible with everything" so end users 
>> will become confused and annoyed and will ultimately not use this. 
>> I'd hence make it explicit and never assume.
>
> All I meant here is that no 'cxxstd' field for a library means C++03 
> as the minimal level. How we decide to display this to the end-user 
> can be discussed and I will go along with whatever others think is 
> best. Obviously we can display the library information by specifying 
> C++03 as the minimal level, or adversely we can display nothing for 
> that given library as a C++ minimal standard level, including even the 
> mention of a "Minimum C++ standard compilation level', and let the 
> user assume that since nothing is displayed the library is usable with 
> any C++ standard level.
But that would be wrong, wouldn't it? A C++11 library which hasn't 
merged the PR adding the cxxstd field (there are quite some inactive 
ones) would be shown/treated as "C++03 is the minimum required", which 
is not correct.
So I'd rather not display anything if the information is missing to show 
exactly that: No information is available. Authors who care will then 
add this information as appropriate.
>> BTW: This will ultimately end up at (e.g.) 
>> https://www.boost.org/doc/libs/1_75_0/, won't it? Or where would that 
>> be displayed?
> The idea is that upcoming release docs would incorporate the 
> information, but I am not adverse showing this for 1.75 if people want 
> that.
Sorry, didn't mean 1.75 specifically, only this page. So one can rather 
watch https://www.boost.org/doc/libs/develop I guess

BTW: That pages show "Revised $Date$" at the bottom

And the new field needs to be added at 
https://www.boost.org/development/library_metadata.html

>>
>> If so the field "Standard" should be clarified. I'm not sure what it 
>> means here and it often is empty (which I'd simply remove)
>
> I agree, and some better, and longer phrase than just 'standard' 
> should probably be chosen. I do believe the phrase was meant to 
> specify the C++ standard release in which the library was accepted as 
> a C++ standard library, but I have no idea what meta information, with 
> what sort of value, was supposed to supply this information.

I would just remove it. On the above docu page it says:

    std: A list of the standardization status of the library. Currently
    just supports 'tr1' for included in TR1 and 'proposal' for a current
    proposal. Will add more in the future..

At the current state "more" wasn't added and all information is pretty 
much outdated