Programming *

The goal of this quick reference is to collect in one place and organize information about value categories in C++, assignment, parameter passing and returning from functions. I tried to make this quick reference convenient to quickly compare and select one of solutions possible, this is why I made several tables here.

For introduction to the topic, please use the following links:

C++ rvalue references and move semantics for beginners
Rvalues redefined
C++ moves for people who don’t know or care what rvalues are
Scott Meyers. Effective Modern C++. 2015
Understanding Move Semantics and Perfect Forwarding: Part 1
Understanding Move Semantics and Perfect Forwarding: Part 2
Understanding Move Semantics and Perfect Forwarding: Part 3
Do we need move and copy assignment

The story of another ban.

Have you heard about bans on apps and developers in Google Play? This is just such a story. It’s also an attempt to collect similar cases into one place and offer some kind of plan of action to prevent Google’s unpredictable actions. It isn’t fair to be banned for the legal use of free material. Personally, I like the idea of content licenses such as CC BY-SA, which permits any use, including commercial. Thanks to such licenses, we developers have websites like StackOverflow, where I’ve been elected to be the moderator. Unfortunately, companies like Google don’t respect the ideas behind these licenses. Here's my story.

In the first part, we have deployed a simple dynamic CDN for broadcasting WebRTC streams to two continents and have proved on the example of a countdown timer that the latency in this type of CDN is actually low.

In the second part, we have incorporated dedicated servers into the CDN for performing the task of transcoding in order to provide good broadcast quality to our viewers based on the devices they use and the channel quality. In this manner, all published streams in our CDN are available to all the viewers.

Now, assume that a company is starting to introduce its monetization strategy where a number of streams should be available for free and the rest on a subscription basis. Or, for example, webinars for in-house staff training are broadcasted simultaneously, but each subsidiary has a separate stream, and disclosing the sales techniques used in Southeast Asia to the managers from CIS countries is undesirable.

Visual Studio IntelliCode uses machine learning to offer useful, contextually-rich code completion suggestions as you type, allowing you to learn APIs more quickly and code faster. Although IntelliCode’s base model was trained on over 3000 top open source C# GitHub repositories, it does not include all the custom types in your code base. To produce useful, high-fidelity, contextually-rich suggestions, the model needs to be tailored to unique types or domain-specific APIs that aren’t used in open source code. To make IntelliSense recommendations based on the wisdom of your team’s codebase, the model needs to train with your team’s code.

Earlier this year, we extended our ML model training capabilities beyond our initial Github trained base model to enable you to personalize your IntelliCode completion suggestions by creating team models trained on your own code.

In the first part we have deployed a simple dynamic CDN for broadcasting WebRTC streams to two continents and have proved on the example of a countdown timer that the latency in this kind of CDN is actually low.

However, besides low latency, it is important to provide good broadcast quality to users. After all, this is what they are paying for. In real life the channels between Edge servers and users can differ in bandwidth capacity and quality. For example, we are publishing a 720p stream at 2 Mbps, the user is playing it on an Android phone using 3G connection in an unstable signal reception area and the 360p maximum resolution that provides smooth picture at 400 Mbps is 360p.

Do you know there were 5 million apps in 2019? Out of these millions of apps, only a few are able to perform. There are many reasons for this but a major factor is the interactivity of an app.

No matter which product you are trying to sell, customers choose the one which allows them to get involved. Interactive apps are in demand for a long time. Are you wondering how can you make an interactive app?

The first thing which comes to our mind when we talk about interactive apps is the concept of single page application. This is because SPAs are known for their capacity to interact with the user by reloading some page elements dynamically depending upon the interaction by the user.

Being a developer, I love to code especially in JavaScript. As per my experience, using reduce function is one of the toughest tasks in JS. Let me first elaborate on the Reduce concept!

In Wikipedia, it has many names viz.

Reduce
Fold
Accumulate
Aggregate
Compress

It is a function that folds a list into any data type. It's all about breaking a structure down into a single value. It's like folding a box! With reduce, you can turn an array [1,2,3,4,5] into the number 15 by adding them all up.

Nowadays everyone knows about cloud services. Many companies have cracked this market segment and created their own cloud services of various purposes. Recently our team has also been interested in these services in terms of integrating the PVS-Studio code analyzer into them. Chances are, our regular readers have already guessed what type of project we will check this time. The choice fell on the code of Huawei cloud services.

Having analyzed earlier the capacity of standard server configurations in Digital Ocean in terms of WebRTC streaming, we have noticed that one server can cover up to 2000 viewers. In real life, cases when one server is insufficient are not uncommon.

Assume gambling amateurs in Germany are watching real-time horse races in Australia. Given that horse races are not only a sports game but also imply big gains on condition that field bets are made at the right time, the video has to be delivered with lowest possible latency.

Another example: A global corporation, one of FCMG market leaders with subsidiaries in Europe, Russia and Southeast Asia, is organizing sales manager training webinars with live streaming from the headquarters in the Mediterranean. The viewers must be able to see and hear the presenter in real time.

Popular cloud hosting DigitalOcean has recently launched its new marketplace selling preconfigured images that can help to quickly deploy an application server. It’s much like AWS, but DO is for those already using this provider’s services. Let’s see how to deploy a simple server for WebRTC streaming with a DO account for a $10/month fee based on Flashphoner WebCallServer and how such a server can be of use.

What is Swoft?

Swoft is a PHP high performance microservice coroutine framework. It has been published for many years and has become the best choice for php. It can be like Go, built-in coroutine web server and common coroutine client and is resident in memory, independent of traditional PHP-FPM. There are similar Go language operations, similar to the Spring Cloud framework flexible annotations.

Through three years of accumulation and direction exploration, Swoft has made Swoft the Spring Cloud in the PHP world, which is the best choice for PHP's high-performance framework and microservices management.

Github

https://github.com/swoft-cloud/swoft

In June, we heard about SwiftUI for the first time — a totally new way of creating and working with UI elements in iOS and macOS (also iPadOS) apps. It felt like Christmas in the summer. It's new, it's declarative, it's sexy! And now, just a few weeks after iOS 13 has been released, we can start to use SwiftUI in all our projects. Let's learn how to use this amazing tool that Apple gave us, to create the classic Tinder-esque Swipe Cards.

In this article, I would like to show you how to achieve a Tinder-like card view and behavior (swipe to action), with just a few lines of code.

To achieve this, we need to do the following things, in order:

• Create UserView
• Create NavigationView
• Create BottomBarView
• Create SwipeView
• Put all this together inside ContentView

So let's get started.

Hi! Though the 2019 conference season is not over yet, we'd like to talk about the bug-finding challenges we offered to visitors at our booth during the past conferences. Starting with the fall of 2019, we've been bringing a new set of challenges, so we can now reveal the solutions to the previous tasks of 2018 and the first half of 2019 – after all, many of them came from previously posted articles, and we had a link or QR code with information about the respective articles printed on our challenge leaflets.

When you think about Jupyter Notebooks, you probably think about writing your code in Python, R, Julia, or Scala and not .NET. Today we are excited to announce you can write .NET code in Jupyter Notebooks.

Try .NET has grown to support more interactive experiences across the web with runnable code snippets, interactive documentation generator for .NET core with dotnet try global tool, and now .NET in Jupyter Notebooks.

We’re announcing .NET Core 3.1 Preview 2. .NET Core 3.1 will be a small and short release focused on key improvements in Blazor and Windows desktop, the two big additions in .NET Core 3.0.. It will be a long term support (LTS) release with an expected final ship date of December 2019.

You can download .NET Core 3.1 Preview 2 on Windows, macOS, and Linux.

• .NET Core 3.1 Preview 2 SDK and Runtime
• Docker images

ASP.NET Core and EF Core are also releasing updates today.

Visual Studio 16.4 Preview 3 and Visual Studio for Mac 8.4 Preview 3 are also releasing today. They are required updates to use .NET Core 3.1 Preview 2. Visual Studio 16.4 includes .NET Core 3.1, so just updating Visual Studio will give you both releases.

Details:

• .NET Core 3.1 release notes
• GitHub release
• GitHub issue for Preview 2

It is a new selection of tips and tricks about Python and programming from my Telegram-channel @pythonetc.

← Previous publications


If you want to iterate over several iterables at once, you can use the zip function (it has nothing to do with ZIP file format):

Photo by Dugan Arnett on Boston Globe

Are you still looking for a new flat? Ready to make the last attempt? If so  -  follow me and I show you how to reach the finish line.

This is a guest post from the Orleans team. Orleans is a cross-platform framework for building distributed applications with .NET. For more information, see https://github.com/dotnet/orleans.

We are excited to announce the Orleans 3.0 release. A great number of improvements and fixes went in, as well as several new features, since Orleans 2.0. These changes were driven by the experience of many people running Orleans-based applications in production in a wide range of scenarios and environments, and by the ingenuity and passion of the global Orleans community that always strives to make the codebase better, faster, and more flexible. A BIG Thank You to all who contributed to this release in various ways!

SameSite is a 2016 extension to HTTP cookies intended to mitigate cross site request forgery (CSRF). The original design was an opt-in feature which could be used by adding a new SameSite property to cookies. It had two values, Lax and Strict.

Setting the value to Lax indicated the cookie should be sent on navigation within the same site, or through GET navigation to your site from other sites. A value of Strict limited the cookie to requests which only originated from the same site. Not setting the property at all placed no restrictions on how the cookie flowed in requests. OpenIdConnect authentication operations (e.g. login, logout), and other features that send POST requests from an external site to the site requesting the operation, can use cookies for correlation and/or CSRF protection. These operations would need to opt-out of SameSite, by not setting the property at all, to ensure these cookies will be sent during their specialized request flows.

Google is now updating the standard and implementing their proposed changes in an upcoming version of Chrome. The change adds a new SameSite value, «None», and changes the default behavior to «Lax». This breaks OpenIdConnect logins, and potentially other features your web site may rely on, these features will have to use cookies whose SameSite property is set to a value of «None».

However browsers which adhere to the original standard and are unaware of the new value have a different behavior to browsers which use the new standard as the SameSite standard states that if a browser sees a value for SameSite it does not understand it should treat that value as «Strict». This means your .NET website will now have to add user agent sniffing to decide whether you send the new None value, or not send the attribute at all.

Since the release of Blazor Server with .NET Core 3.0 last month lots of folks have shared their excitement with us about being able to build client-side web UI with just .NET and C#. At the same time, we’ve also heard lots of questions about what Blazor Server is, how it relates to Blazor WebAssembly, and what scenarios Blazor Server is best suited for. Should you choose Blazor Server for your client-side web UI needs, or wait for Blazor WebAssembly? This post seeks to answer these questions, and to provide insights into how Blazor Server performs at scale and how we envision Blazor evolving in the future.

What is Blazor Server?

Blazor Server apps host Blazor components on the server and handle UI interactions over a real-time SignalR connection. As the user interacts with the app, the UI events are sent to the server over the connection to be handled by the various components that make up the app. When a component handles a UI event, it’s rendered based on its updated state. Blazor compares the newly rendered output with what was rendered previously and send the changes back to the browser and applies them to the DOM.