C++/library requirements for Plasma 5.26

[Ivan Čukić]

Hi Nicolas,

While I've been known to request newer and newer compilers
for everything, and while I do support this request for GCC 10
and Clang 11, I'm not sure I'd support requiring QCoro and
coroutines.

Not because of QCoro itself, but that clang doesn't yet officially
support coroutines. According to [1] they have a partial support
since version 8, and according to [2] they might lead to problems
when coroutines might be resumed on a wrong thread (if I'm
reading this correctly), with a comment 'This feature requires
further analysis of the C++ Standard to determine what work is
necessary for conformance.'

Clang development seems to have slowed down a bit so I'm
not sure how viable is pushing C++20 to Plasma just yet.
Especially since most of us compile with GCC - if we are able
to overlook bugs that our patches introduce for dark-theme
users because we use and test on the light one, I can't dare
to imagine issues we can introduce to Clang-based distros. :)

Cheers,
Ivan

p.s. From a personal standpoint, yes, I'd really like to be able to
use QCoro in Vault...

[1] https://en.cppreference.com/w/cpp/compiler_support/20
[2] https://clang.llvm.org/cxx_status.html

-- 
dr Ivan Čukić
ivan.cukic at kde.org, https://cukic.co/
gpg key fingerprint: 8FE4 D32F 7061 EA9C 8232  07AE 01C6 CE2B FF04 1C12