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CppCon 2017: Programming with C++ Constraints: Background, Utility, and Gotchas--Walter E. Brown

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Programming with C++ Constraints: Background, Utility, and Gotchas

by Walter E. Brown

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Compile-time constraints will likely soon become part of our routine C++ programming vocabulary. Why? Such constraints are induced by new core language features (requires-clauses and requires-expressions) that are on the horizon for C++. What are these all about?

Almost every function imposes requirements on its users; violating those requirements typically leads to incorrect programs. Historically, such requirements had to be expressed in comments or other documentation, as there was little machinery to express them in code. Soon we will be able to express more requirements in code, thus allowing compilers to detect and address more violations.

This talk aims to prepare both new and veteran C++ programmers with the necessary background, tutorial information, and advice to exploit this powerful new supplement to function declarations. A case study, illustrating an unexpected gotcha, will conclude the presentation.

CppCon 2017: Undefined Behaviour is awesome!--Piotr Padlewski

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Undefined Behaviour is awesome!

by Piotr Padlewski

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Undefined behavior (UB) is one of the features of C++ that is both loved and hated. Every C++ developer cares about performance, which is why it is very important to understand what the compiler can optimize and what are the language guarantees. Many times programmers are too optimistic about what the compiler can optimize, or they waste time optimizing code by hand.

In this talk you will learn:
- what is the “as-if” rule
- why compilers know less than the programmer — the main problem with Translation Units
- why compilers optimize based on UB, but don't warn about it
- why Undefined Behavior can transcend time, removing your whole code without running 88mph
- why having a more constrained language is better — optimizations that you can’t do in C

CppCon 2017: Seventeenification: Porting sqlpp11 to C++17--Roland Bock

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Seventeenification: Porting sqlpp11 to C++17

by Roland Bock

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

The ink on C++17 has merely dried, but the major compilers support most features already. It's high time for a reality check!

This talk is a report about the ongoing effort of porting sqlpp11 to C++17. I'll show real-world usage of the following features:

Core:
inline variables
auto non-type template parameters
[[nodiscard]]
class template deduction
constexpr if
fold expressions

Library:
string_view
optional

This talk also comes with a realization about C++11.

Top11 Talks and other voting results for Meeting C++ 2018

The voting for the talks at Meeting C++ 2018 ended, and the results are in!

Voting results for Meeting C++ 2018

by Jens Weller

From the article:

On Sunday the voting ended for this years conference. And the results are interesting, each talk received between 87 and 104 votes from 147 active voting sessions. In total its 10685 votes casted. So lots of folks did have a look at each talk, the average of the collected votings is then what determines the top talks at the conference...

CppCon 2017: Delegate this! Designing with delegates in modern C++--Alfred Bratterud

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Delegate this! Designing with delegates in modern C++

by Alfred Bratterud

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Designing a fast IP stack from scratch is hard. Using delegates made it all easier for IncludeOS, the open source library operating system written from scratch in modern C++. Our header-only delegates are just as fast as C-style function pointers, compatible with std::function, and allows any object to delegate work to stateful member functions without knowing anything about the class they belong to. We use delegates for everything from routing packets to creating REST endpoints, and most importantly to tie the whole IP stack together. In this talk we’ll show you how we use delegates in IncludeOS, discuss pitfalls and alternatives, and give you all you need to get started.

CppCon 2017: Coroutines: what can't they do?--Toby Allsopp

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Coroutines: what can't they do?

by Toby Allsopp

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Coroutines are coming. They're coming for your asynchronous operations. They're coming for your lazy generators. This much we know. But once they're here, will they be satisfied with these offerings? They will not. They will require feeding, lest they devour our very souls. We present some fun ways to keep their incessant hunger at bay. I, for one, welcome our new coroutine overlords.

The Coroutines Technical Specification is an experimental extension to the C++ language that allows functions to be suspended and resumed, with the primary aim of simplifying code that invokes asynchronous operations. We present a short introduction to Coroutines followed by some possibly non-obvious ways they can help to simplify your code.

Have you ever wanted to elegantly compose operations that might fail? Coroutines can help. Have you ever wished for a zero-overhead type-erased function wrapper? Coroutines can help. We show you how and more.

Slides of the 28th of June 2018 BeCPP Meeting -- Marc Gregoire

BeCPP_Logo_282x64.pngOn June 28th 2018, the Belgian C++ Users Group had their next event sponsored by Western Digital.

Slides of the 28th of June 2018 BeCPP Meeting

About the event:

  • "Strongly Typed Declarative Bitsets in C++17" (Ewoud van Craeynest)
  • "The Observer pattern and boost.signals2" (Lieven de Cock)

If you couldn’t attend the event in person, or if you would like to go over the material again, you can download them from the BeCPP website.