[Development] QtCS 2017 QtCore sessions
Allan Sandfeld Jensen
kde at carewolf.com
Mon Dec 4 20:29:25 CET 2017
On Montag, 4. Dezember 2017 15:30:49 CET Ville Voutilainen wrote:
> On 4 December 2017 at 16:20, Allan Sandfeld Jensen <kde at carewolf.com> wrote:
> > On Montag, 4. Dezember 2017 15:00:53 CET Marc Mutz wrote:
> >> Ah, well, yes. Nothing truly originates in C++, true. But, IIRC, the
> >> Haskell name is maybe. So why is it QOptional and not QMaybe? Because
> >> the C++ interface is used as the basis, not something from Haskell.
> > I believe the name "optional" comes from Haskell and Java where it
> > appeared
> > first. The standard library only imports things that are already industry
> > standard, and once there were several implementations of optional out
> > there, they started to pull one in. They just didn't manage to write it
> > without using C++17'isms.
> std::optional has no fundamental c++17isms in it, and can be written
> without any problem in C++11 code.
> I maintain optional in libstdc++, in case you wonder on what basis I'm
> making that statement.
I know it can be written with C++11. I have both seen it, and done it myself.
I was just noting the C++17 version takes advantage of C++17 (which makes
sense). I did not mean to imply you couldn't or hadn't. I am sorry if I
formulated that wrongly.
> The standard library imports a whole host of things that aren't always
> industry standards. but it imports things only when there's a proposal
> to import something.
For this part I was refering call for proposals http://cplusplus.github.io/
LWG/call-for-library-proposals.html which says it strongly prefers things
based on existing practice.
Anyway. I was just taking offense at Marc's claims that Qt was "stealing from
C++" by adopting similar compatible ideas as the standard library, but made
available for our supported platforms in our time frame. It made little sense
to me, as you might as well argue Qt is stealing from Windows and Mac, by
making a cross-platform toolkit implementing their established practices.
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