Meeting[1] // "A Polymorphic Value Type" & "Anti: Signed for Life"

After the phenomenal success of our first meet-up we now have another pair of talks lined up for January.

Once again we're being hosted by the great folks at SkillsMatter - so please register on the SkillsMatter page too as they require this for entry (https://skillsmatter.com/meetups/8890-c-plus-plus-london-january-meetup).

Here's the agenda for the evening:

18:30 pre-session networking, including drinks at the bar if you like

19:00 Phil Nash (https://www.meetup.com/CppLondon/members/48127252/) << "Hello World"

Brief introduction and raffle for a JetBrains license (if I remember this time!)

19:15 Tony Lewis (https://www.meetup.com/members/202550546/) << "Anti: Signed for Life (a response to Jon Kalb's 'unsigned: A Guideline for Better Code' talk)"

At CppCon 2016, Jon Kalb gave a very interesting Lightning talk, entitled. “unsigned: A Guideline for Better Code", in which he argued against the use of unsigned types (except for bit-masks). Indeed it appears that majority of C++ expert opinion agrees with him. Yet, I haven't yet heard arguments that seem to be adequately convincing. So with all due humility and with blessing from Jon (and James McNellis), I want to argue the opposite case (that unsigned types have their place) if only to move the public conversation forward so that everyone clearly understands why I'm wrong. In this talk, I will argue that (1) shunning unsigned types is the wrong solution to the core problem that Jon identifies and that (2) with the correct solution in place, the benefits of unsigned types will often outweigh their costs. I intend to make a video of these arguments soon so I'm eager to hear the feedback and discussion in this London meetup so I can improve that video.

19:45 // Questions, hand-over, break

20:00 Jonathan Coe (https://www.meetup.com/CppLondon/members/187960610/) << "A polymorphic value-type for C++"

The class template polymorphic_value is proposed for addition to the C++ Standard Library.
The class template, polymorphic_value, confers value-like semantics on a free-store allocated object. A polymorphic_value may hold a an object of a class publicly derived from T, and copying the polymorphic_value will copy the object of the derived type.
I will present the design and reference implementation, all of which is available here https://github.com/jbcoe/polymorphic_value

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We'll finish around 20:45-21:00 at which point we'll adjourn to the bar for more informal discussion and networking.

About the speakers:

Tony Lewis has been programming computers for something close to 30 years. At university, he studied maths and then later, intelligent systems, with a couple of years at IBM in between. Since that, he's spent much of his time at University College London, working in a bioinformatics group that curates CATH, a hierarchical classification of protein structures. His real interest is getting computers to do more interesting things by getting them to evolve solutions themselves and he earned his PhD in this area. He'd love to find ongoing funding to continue that research. Whilst using C++ in all these different areas, he's slowly found himself being frustrated by it less and less and loving it more and more. Tony is open to offers of short-term C++ work.

Jonathan is a mathematical developer using modern C++ and Python. He has worked in academia and the financial and energy industries. He's been a participant in the C++ standards committee since 2014.