CppCast - Meeting C++

Episode Date: April 1, 2016

Rob and Jason are joined by Jens Weller to discuss the Meeting C++ conference and user group community. Jens Weller is the organizer and founder of Meeting C++. Doing C++ since 1998, he is an active member of the C++ Community. From being a moderator at c-plusplus.de and organizer of his own C++ User Group since 2011 in Düsseldorf, his roots are in the C++ Community. Today his main work is running the Meeting C++ Platform (conference, website, social media and recruiting). His main role has become being a C++ evangelist, as this he speaks and travels to other conferences and user groups around the world. News Compiler Bugs found when porting Chromium to VC 2015 Practical Guide to Bare Metal C++ Concepts without Concepts Jens Weller @phlox81 Jens Weller LinkedIn Links Meeting C++ Announcing Meeting C++ 2016 Learning C++ Best Practices - Write Simpler, Faster, More Maintainable Code

This episode of CppCast is sponsored by Undo Software. Debugging C++ is hard, which is why Undo Software's technology has proven to reduce debugging time by up to two-thirds. Memory corruptions, resource leaks, race conditions, and logic errors can now be fixed quickly and easily. So visit undo-software.com to find out how its next-generation debugging technology can help you find and fix your bugs in minutes, not weeks. CppCast is also sponsored by CppCon, the annual week-long face-to-face gathering for the entire C++ community.

Get your ticket now during early bird registration until July 1st. Episode 51 of CppCast with guest Jens Veller, recorded March 29th, 2016. In this episode, we talk about compiler bugs and concepts without concepts. Then we talk to Jens Weller from Meeting C++. Jens talks to us about the Meeting C++ developers by C++ developers. I'm your host, Rob Irving, joined by my co-host, Jason Turner. Jason, how are you doing today? I'm doing good, Rob. How about you?

Doing pretty good. So last week, Jason, you announced that you had started your own YouTube channel. And you have another side project that you wanted to share this week, right? Yeah, so just a couple of weeks ago, I officially released my first project with O'Reilly Media, which is a video training series on C++ best practices. Awesome. I have no idea how well that's selling or anything yet, but it was an interesting project to work on. And was this somewhat based on the CPP best practices website that you started a while back? Yes, it's definitely inspired by what I did there, and I'm also mixing some stuff from the C++ Core Guidelines.

Awesome. Awesome. Well, I'll put a link to that in the show notes. I definitely recommend everyone go check it out. So, at the top of our episode, I threw a piece of feedback. This week, Dan wrote to us on Twitter, and he said he just listened to the Artillery CppCast episode. That was one with Mark Logan. We did it a couple months back in January, and he says, really cool stuff, well explained. Those JavaScript and C++ episodes have definitely

turned out to be pretty popular. That's interesting, yeah. Well, we'd love to hear your thoughts about the show as well. You can always reach out to us on Facebook, Twitter, or email us at feedback at cppcast.com. And don't forget to leave us reviews on iTunes. Joining us this week is Jens Veller. Jens is the organizer and founder of Meeting C++. He's been doing C++ since 1998. He's an active member of the C++ community. And from being a moderator at C++.de, an organizer of his own C++ user group since 2011 in Dusseldorf, his roots are in the C++ community.

Today, his main work is running the Meeting C++ platform, including the conference, website, social media, and recruiting. And his main role has become being a C++ evangelist. As this, he speaks and travels to other conferences and user groups around the world. Jens, welcome to the show. Hi. Nice to be on C++. Thanks for joining us. Well, we had a couple of news articles we wanted to talk about.

Jens, feel free to chime in on any of these, and then we'll start talking to you about all the great work you've been doing. This first one is about compiler bugs found when porting Chromium to VC 2015. And I guess this comes from someone on the Google team who was working on porting the Chromium project to Windows. And he found several compiler bugs while doing this. And he wrote about some of the specific bugs. And he also just wrote about the process of reporting these bugs to Microsoft. And if you do ever find bugs with Visual Studio's compiler, if you give them a nice reproducible test case, they apparently are very, very good at addressing that bug. Maybe a little bit better when it's coming from Google, but I think they're pretty good with anyone reporting bugs if they have a nice test case to work with.

Yeah, he also mentions in the comments that being an MVP helps also. Yes, this is true. But he really makes it sound like if you have a nice, easy-to-reproduce test case, that they'll get on it. Yeah, there's an interesting article. There was, uh, in the comments, someone mentions a tool called, um, Delta debugging or an I it's a sweet, an idea of tools called Delta debugging. And, you know,

I'm like a huge tools guy and I'd never heard of this before. And it's, uh, the idea is tools that can automatically reduce your test code down into something that still reproduces the bug. Oh, that's interesting. And there's a couple of links to some open source ones that work with C++ that can do that, and I have got to check that out at some point. So that'd be a great way of creating these small reproducible test cases. Theoretically. But apparently large binary search kind of things where it's removing code until it... So it could take a very long time to run,

but it's interesting. And it would be run automatically. It wouldn't be you running it and testing everything out manually. Theoretically, anyhow. Very cool. Jens, was there anything you wanted to comment on with this? This post reminds me of a similar post

where somebody drew comparisons to LTO and compiling LibreOffice with GCC and Clang. So I think compiling large projects with newer compiler versions is always an interesting thing which shows up all kinds of bugs or new things or different angles, which probably don't show up in our everyday projects. Yeah. What was the size of the Kermian project?

I think I saw it was like 90,000 code files, something like that, or 48,000 C++ files and 40,000 headers. And also it says over 100 open source projects are also pooled in by it. Wow. It's a very large project. Yes. Okay. This next one is a practical guide to bare metal C++. And probably not going to go into too much detail on this one, but it's worth pointing out in case you're interested

in doing some embedded programming where I believe C is still very popular in the embedded world. But I think the point of this guide is to showcase some of the advantages using C++ in that kind of environment. Yeah, it looks like a pretty extensive document. Yeah, and the link I'm going to put in the show notes, it's to a gitbook.com address where you can get a PDF

or a Kindle format so you can read this as a book. You don't need to just read it on the website, which is nice. I've never heard of Gitbook before. I'm actually using it to host a version of CppVest practices. Is it just hosted from a GitHub repo and they give you this extra stuff to get you the PDF and the Kindle stuff out of it? Yes, it uses the markdown

in your GitHub repo. Very nice. What were you going to say, Jens? Last year we had the embedded as a theme track at Meeting C++, so that's definitely a hot topic, an interesting topic, but it's also very constrained by the industry, so that the advantages of using C++, I think it's a very, very good overview and how you can apply C++ to the embedded domain. But a lot of the industry is not able to actually move forward into that

because of their constraints internally in the industry. So it's always very interesting to talk to those people from the embedded domain as it's a completely different world. Right. So what was your experience from the conference? Did you go to any of those talks about the embedded stuff yourself? I think I've been to

one talk from Bordafonon. During the conference, I'm usually very busy, and I have seen most talks while editing. Right. That's kind of, you know, I get to see most talks then when I edit the videos. I'll have to go and look at those talks and see who you had as speakers,

because that's one topic we still have not really gone into too much depth on in the show, embedded development in C++. Yeah, we talked about it early on, and I never really got any guests on. Yeah, yeah. And this last article is a blog post on concepts without concepts. We're not going to be getting concepts in C++ for a while, and this author was going over some ways that a library developer could kind of give you some of the features of concepts without using it, I guess. Jason, would you say that's a good

way to characterize this article? Yes, I would say that's a good way to characterize the article. I actually had this in the back. I didn't thoroughly read the article when I first saw it on Twitter, but I had it in the back of my mind when I was just adding a new feature to ChaiScript. And I'm like, okay, I need to put a static assert at the top of this template so that our users have an actual reason why this is failing. Right. And he goes on beyond this static assert method. Yes. he goes on beyond this static assert method and you could actually just turn off the functionality in your method if the

constraints are not met and then you wouldn't get the really ugly compiler errors that we all know and love that are associated with bad template code. Right. You get less you can enable if it's nice but it can Well, you get less. Right.

You can enable if it's nice, but it can really get you, pull your hairs out when you get into overload resolution things. And I had one case a few weeks ago where I overloaded for null pointers, and this made then enable if fail. And so I had to remove the overload for null pointers, and this made then enable if fail. And so I had to remove the overload for null pointers and do it somehow else. Or just also to, if you use enable if, you have to do it on almost everything and everywhere. And it can get kind of tedious to select the right functions

in every use case. Yeah, that's the kind of thing sometimes with enableF, I still feel like I'm just trying random things until I get the compiler to do what I want it to do. Like, it's not, I don't feel like I always 100% understand exactly what I'm asking for. Right. So, sorry, what was that, Jens?

Yeah, regarding concepts, I got an interesting feedback last year at C++ Now. For a while, concepts have been available in Boost as a library, Boost concepts. And also Eric Niebler has in his range library version, I think he has re-implemented concepts in his own macros. And so if you want to make use of these things, it's available for a while and it's been used in some libraries, but I also have seen people say, well, maybe concepts is not that important as it's been available through Boost library or other meanings and it's not used that heavily. And that's actually one of the few negative views on concepts I only could find. And there's a lot of hype.

And I hope we really have concepts soon in other compilers available, not just GCC6. Yeah, you know, I feel like it is kind of important, at least for the standard library, to have concepts, particularly for new users of C++, because sometimes you just get a wall of errors that can take a very long time to parse. And if we can get past that, that would be great. Yes, I agree on that totally. So Jens, let's start talking about meeting C++. In your bio, you talked about how you've been writing C++ since 1998.

How did you go about going from just a normal C++ developer to becoming the C++ evangelist, as you put it? Well, I've been interested in C++ since I've kind of, by accident, turned into a C++ programmer in my high school. And so for a long time, my home or my heritage regarding C++ has been an online community, an online forum. Like, you know, like in the beginning of the 2000s, a lot of people probably have, you know, had their online forums. And so I've been for a long time a member of C++ DE which is now C++.net and over time I have become involved in the organization

like being a moderator for a forum and then with the user group that started when I was self-employed, I had started doing community work for Linux-based mobile OS, which is also a little bit of my background as I have worked for Vodafone in the past. And so during that time, I kind of learned the basics of community work, which I already had some basics from the online phase and then the offline work with user groups but also then later when MeeGo was discontinued I thought it would be nice to to continue this work for C++ itself and not anymore for any vendor or anything new coming up or any other platform and so in 2011 the C++ user group in Dusseldorf got started and as a almost, yeah, it looks a bit like a follow-up to today but it's just in 2012 I was visiting C++ now for the first time and I've been talking to a few people how they organized the conference,

and I kind of got the feeling that with the user group and my connections I had through the community work, we'd be able to organize a similar event. That's how Meeting C++ got started. So for how long has this been your full-time effort being the evangelist community organizer Meeting C++ got started. So for how long has this been like your full-time effort being the community evangelist, community organizer for C++? I think it's kind of since 2014, it's 100% that I only do this. It's been two years. And originally I have been a freelancer for C++.

And in 2013, I kind of could figure out that freelancing and organizing a conference does not go well together as the conference often requires a certain amount of time that are not available to clients, and clients usually want 100%. And it's hard to sell only like two or three months and they're like it's most projects are like at least six months and they were like don't care if you're you know if you have a hobby like as a witness organizing a conference and also i figured out that if i wanted to to do the the work for user groups, et cetera, more seriously, I would probably have to take on a different model.

And so I kind of figured out if the conference grows large enough, I can make this like a crowdfunding that my work for the community is funded through the conference and my job more or less today is to maintain the network behind meeting C++ for C++ and this always has its roots in 2012 when the world was like still very very different we had a new standard but most people did not have a lot of high expectations on the standard as it just was, you know, the standardization was really, really weak for the past years. And now we had a new standard and people expected that for the next five or six years, we would not have another standard. People did not expect that standardization would actually catch up and do things like that. And also back then, ISOCpp.org did not exist.

And so one of the things which I always have seen is that C++ has, as a free language, a certain lack in marketing and organization of things like community. And I thought, well, if I have a conference and have a conference website, I don't want the conference website to be down for like six months and then suddenly it's, hey, we have a conference again. And so I thought about how to use the conference

as a tool for the community to motivate people to get user groups started and to get more information out about C++ to other people, which not everybody is able to go to the conference. Right. So I think most of our listeners

are probably already somewhat familiar with meetingcpp.com, but could you maybe go over everything that's involved with Meeting C++? There's the conference, there's a website. What else is there? Yeah, the website is, I think today the interesting points on the website are this year's conference, which will be announced in the next day, so when the episode is up up people should be able to find it on the website and um then there's my blog where i do block the these things which i do with c++

which is currently mainly building a cms for the website um and then there's a section for user for user groups which um shows if there is a local user group in your area. And there's, of course, a news section. In this news section, you can see which different things are currently happening for Meeting C++, which is mostly the conference. But I also post once a month an overview on upcoming user group meetings for the next coming months. So the next posting in the next few days after the announcement

will be this post handling the user group meetings for April. Would you be okay with sharing that date now? Because we're not going to publish this episode for a few days. Oh, that's already known. It's 18th to 19th November.

Okay. And yeah, this year's conference, the track, the theme track will be Game Dev, and the keynote will be held, the opening keynote will be held by Jan Strauss' group, and for the second

keynote, I'm still thinking about who should do it. Okay. Very cool. So, where is it going to be held this year? Berlin again? Yes. Okay. For this and probably next year I'm staying in Berlin.

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Yes. How's that going? It takes a bit longer than I thought. It's a serious rabbit hole to go down through, but I'm pretty far. And I actually currently have a prototype which works and already spits out working websites without CSS, et cetera. But I still have to improve it a lot to actually be able to port my website. And one thing I've been working on in the last weeks has been an API for accessing JSON libraries through generic code.

And so originally I planned to have the website first done and then announce a conference, but that hasn't worked out. So I will redo the website in summer. And currently it's in the prototype phase pretty far. Is this going to be an open-source project? Are you going to let all the C++ bloggers out there use your CMS to make their websites? I plan to open-source this,

but I'm not sure if this workflow is like for... For me, it's an internal tool, so I'm not sure if the workflow is really the thing which people are looking for the CMS currently has a front-end built on Qt as a UI where I will then build my website with and you have to be pretty familiar with that workflow which I've been for years it's kind of you know like I would like to the good parts of the tool which I'm using currently is basically ported into into Qt and on the other hand I plan to to split this into a library part which

then you know you could use to build something like Jekyll or something which I currently don't aim at building something like Jekyll or something, which I currently don't aim at building something like Jekyll. And yeah, so the CMS is for static pages. It's not for dynamic content. So at the end, it's a website generator, and the website is then uploaded via any connection to the network and served via any web server. So I just moved my personal site to Jekyll, and there seems to be a lot of moving towards statically compiled web pages. Is that the route your CMS is going? I'm just curious. Is it statically or is it database?

It's okay. That's interesting. I've been thinking about, since last year, January, what to do and what route to go down. And at the end, I thought, well, just build a small CMS for yourself. Then I have like everything in my control because my problem is that I don't want to redo the website every two, three years when the tools are changing again in a new version and often are not really compatible to the previous version like you already could see with Jackal now with Jackal 2 and Jackal 3 and I don't want to fall in that trap to have to redo my website

every few years so that's why I decided it's gonna cost me probably a lot of time to get to that point where I can do that, but I just want to be in 100% control of my own technology stack. That's a decision I made last year. So, okay, since you're building in C++, what's the biggest headache that you've hit so far? I know, for instance, it took you a while to settle on a JSON library to use. It looked like, anyhow, from your tweets. Yeah, well, the JSON libraries, I looked too far to make JSON libraries how they were implemented,

and I even found out that there is two libraries with the same name. Oh. And I have done my research now with JSON and C++ and I think I'm soon going to blog about it and I kind of started to work on my own API which is the generic API and then uses lots of enable if to kind of drill down the interfaces and the implementation of the other libraries. And so I will be able to plug and play. That's a long time goal to plug and play with like three or four different JSON libraries so that I'm not having to tie my code to a certain JSON library.

And currently I'm going with RapidJSON. We had some questions that came in on Twitter when you announced that you were going to be on the show. Vasily wrote in, it's interesting to hear how you've built this community, and he wanted to know what sorts of benefits and challenges you've had on the way. I think at the beginning,

the first thing at the beginning was the problem to really understand what the whole thing is, what it is today. And I just had the conference and was not sure what to do and what direction to go. Should I have like an online community like other people do? And on the other hand, I to not not to reinvent something which already existed so I've been for a long time and then online forums I know the pain which they bring and I didn't want to have another forum or user generated content on my website and so I think one of the benefits is definitely that I have access to this

vast network of C++ programmers so it makes it interesting if I have like some problem then I can just turn to that network and go and have like people of all kinds of from all over the world turn in and have their opinion on a certain thing and on on the other hand um i've been really interested in how how networks work and how human networks grow and so um it's really interesting to see this from the inside and it's also kind of crazy to see that um the itself has grown, but also the network behind the conference, the followership in social media has now for two years in a row doubled and it's gotten a lot bigger than I thought at the beginning. Wow. And one of my goals definitely from the beginning was to build something like a network

where I am able to share content into the C++ community. I mean, I know how much work it is to blog. I know how much work it is to make videos. And I want to really kind of, like ISOCPP has a similar idea but they're going slightly different route than I do and I'm glad that both of those models exist and that we actually now have ways to really to bring the content to the readers and also to give people which do things like JSON and all this weekly, which is kind of new.

When you started the podcast, I was directly a big fan of that and thought it's probably the best thing I can just do to support you guys is just share it over my network. Yeah, we definitely appreciate that a lot. It definitely helped us find a lot of listeners early on. Yeah, it did. I know you work with a lot of user groups. Are most of the

user groups you work with in Europe, or are there a decent amount in America as well? I think there's a decent amount in Europe and in America. And there's even a user group in Vietnam. There's a user amount in New York and in America and there's even a user group in Vietnam, there's in India, there's one user

group in Sydney and a few others Asia in general is kind of difficult as it has a big difference in culture so that on the usual ways where I look for user groups

they probably I haven't been contacted and I haven't been able to find them because a lot of them are using their own web platforms or organizing differently and maybe they don't meet even because it's a cultural difference or I don't know I know that there's some there has to be some activity in China and there has to be some activity in China and there has to be some activity in Japan and as a fact I know about some activity in Japan and Taiwan. But

for my work mostly I work with user groups in Europe and a little bit in America. So what advice would you have to someone who's looking to start a new C++ user group in their area? Well, my first advice would be to not to try to do it alone.

Try to find a local network which is available to you. And I can help to widen that network to give you contacts which are in your region, which you don't have yet. And with that basis you're probably able to launch a user group quite easily today if you're living in an urban area. And if you're living in an urban area, also maybe do some research if there has been a user group which has been active or maybe there's even an active user group. And then I have a bunch of tips regarding that on my website in the user group section and I have given two talks about it with John Korb and at C++Now and CppCon last year. And it's the most important thing I can give you is get started.

I think it's the most important thing. If you don't get started, it's not going to go anywhere, and you're not going to see if people are interested. Right. So just to dig in one more time, just to make sure I heard you right, because you have this large network of C++ developers with meaning C++, if I was interested in starting a user group in my area, I should reach out to you and you might be able to find a list of other C++ developers in my geographic region that I could work with to start that user group and you could help out just with communicating

with those other developers? Yes, I have done this for a few user groups and I'm very willing to share the network I have with people. And so the newest user group, one of the newest groups is in Sofia. I have been contacted now from a German town called Wiesbaden where now a user group is active. And it can take a little bit to get started. But the main ingredients you need are people. So if you have co-workers, try to get them involved. And you need a location.

A hackerspace can be a great location. Maybe your company has a meeting room which is able to sponsor it and i know that some companies actually sponsor the meetings for reasons like hr and um then you need a date and for the first meetup it's just maybe maybe have a talk maybe don't have a talk just tell people what you what you plan and just make it a planning meeting can be very effective and also gives you a good access to your to your local community which then will you know form your user group and the last thing again which i which i only can really uh point at is if you don't get started you're not going to go anywhere right it's definitely good advice and i imagine if there are any of our listeners who are going to user groups that are not currently listed on meetingcpp.com, you probably want to hear from them to get their user groups added.

Okay. Yeah, meetingcpp.com is definitely a great resource if you want to find out if there is a user group in your area. Also, there's meetup.com. I'm not sure. Is meetup.com popular in Europe for just user groups in general? Yes. Okay. Yes.

So you said that you already have the keynote speaker planned for this year's Meeting C++. Have you done much more planning? Are you already accepting speaker proposals? Yeah. The call for papers is live, and you can find all the information about that also on the website. And this year's theme track is game dev, and I'm generally looking for talks on C++, especially for libraries, for the new standard or the current standards,

like C++11, C++14, if you want to do a certain talk on that. Definitely also looking for talks which you want to do a certain talk on that. Definitely also looking for talks which give an overview on a certain topic or present a certain library and all kinds of C++ related talks. And the call

for papers will be until May 27th. I just want to ask what has your opinion been on all the news coming out of the standardization meetings regarding C++17? I know you've probably read lots and lots of blog posts and different opinions. What are your feelings about it? On the one hand, of course, C++17 is not what we all hoped it would be, which was kind of clear for some time if you knew the committee well like I do. But on the other hand, I'm very glad that we seem to have now a common model to work on the standardization with.

And I think all decisions which have been at the last meeting were very good. And I really like the decision that concepts did not make it in the standard. I think it's the right decision currently, as too many people were critical about it. And we should be careful in what we basically set in stone. And so I'm a big fan of the train model. I think that's the correct model. And I see that the big features which have been, you know, trying to get ready for C++ 17,

most of them are lacking like a year behind. So if you want to stick to the train model, we have to ship C++17 next year and then we have again some time to improve these features even more. And on the other hand, I think that we really should have a different look at the standard as we had it in the past. The technical specifications are actually quite serious and the things which go in a technical specification are meant to be part of the standard. And I think that a technical specification usually has a very stable API

and it's a very solid thing to use in your code. So I think that once once concepts is available as an extension like it is in GCC 6 or like we already have modules, modules exist in the current version and the Microsoft compiler and also Clang had for years a kind of a model of modules so I expect also updates on that front so that if you really need if you really need these features, they're available. And we will have more and better feedback by people using them. And I feel then it's the right time to put them in the standard and not the other way around.

So C++11 had to make a lot of time up for being late and now I think we're on a constant model to ship this each three years, I think is the number mentioned in this last post. And I'm very fine and very good with that number and I think that the actual, the big value of the last five years of standardization for me is that we have now a common model for standardization itself and probably will make a lot easier

to predict the standards after C++17 Okay Jason, do you have any other questions? I don't believe I do Okay, well Jens, I know we can find you on Twitter at meaningcpp and the website meaningcpp.com do you have your own personal Twitter account or blog

that you'd like to share as well yes I do have a personal Twitter account which is floxa1 and I do not have a personal website currently I plan to maybe do that once my CMS is done. Great. Well, it's been great having you on the show. I definitely encourage everyone to go to meetingcpp.com,

check out the conference, check out the videos, check out the user groups. It's a really great website. Thanks for joining us. Thanks for having me. Thanks so much for listening as we chat about C++. I'd love to hear what you think of the podcast. Thanks for joining us. Also appreciate if you can follow CppCast on Twitter and like CppCast on Facebook. And of course, you can find all that info and the show notes on the podcast website at cppcast.com. Theme music for this episode is provided by podcastthemes.com.