The Microsoft unit testing code for managed code allows to create test methods that are executed with data automatically fetched from an external data source. This is very helpful because we can extend the data sets without modifying the test code. An external data source can be an SQL database, a CSV file or Excel document, an XML document, or anything else for which a provider for .NET exists. In this article, I will show how you can define test data using all these types of source and execute unit testing methods with it.
In some situations, we need to makes sure function templates can only be invoked with some specific types. SFINAE (that stands for Substitution Failure Is Not An Error) is a set of rules that specify how compilers can discard specializations from the overload resolution without causing errors. A way to achieve this is with the help of std::enable_if.
Back in mid-August, Microsoft released the 2nd preview of Visual Studio 2019 16.3. This is the first version of Visual Studio to support concepts from C++20 both in the compiler and the standard library (header <concepts>) without the changes made at the ISO C++ standards meeting in Cologne. These changes are available when you compile with the /std:c++latest switch.
Concepts allow performing compile-time validation of template arguments and function dispatch based on properties of types. Concepts are very useful in libraries where they can be used to impose compile-time checks on the template arguments of functions or types. For instance, a generic algorithm for sorting a container would require the container type to be sortable for the program to even compile.
In this article, I will show an example with a concept that verifies that a type T can be converted to a std::string via a to_string() function, that is either a member of the class or a free function.
In the beginning, there was const. And people saw that const was good. And then the people said: let there be constexpr, and consteval, and constinit. And thus, starts this article about constant functions and variables in C++20, which I will try to keep short and concise.
We all know C++ is a powerful yet complex programming language. But it can also be fun. For instance, you can use emojis and other Unicode characters in the source code. Of course, nobody sane would use emojis for identifiers. But it’s possible and you can have a little fun if have some spare time.
Identifiers are sequences of digits, underscores, lowercase and upper case Latin letters, and most Unicode characters. Identifiers are not allowed to begin with a digit, they must begin with an underscore, a Latin letter, or a non-digit Unicode character. For more information about the Unicode characters in identifiers see this.
So here is a little example of a C++ program that uses emojis. Can you figure out what it does?
Some time ago I published a Visual Studio extension called Memeful Comments for displaying images, including animated GIFs, alongside your code to enhance explanations with visuals or simply to express your reaction to the code. This extension is now available for Visual Studio 2019!
A functionality of one of the products I’m working on suddenly stopped working without any code changes on our side. Our application connects to a web service to get some data and that no longer worked, our customers getting the following error in their logs “The underlying connection was closed: An unexpected error occurred on a send.” The first thing to do was checking whether the web service was still up and running as expected. The requests made with SoapUI or Postman were all successful, so it was actually something in our application that was actually wrong. So I decided to use Fiddler to look at how our requests look and what do we get back.
Visual Studio 2017 has had a larger number of updates throughout its lifetime. At the time of writing this article, there have been ten major updates and countless minor ones. You can check the release notes history for details. Part of the changes was in the debugger. In this article, I will mention three features…
The post-Kona mailing list of the new standards papers has been recently published (you can find it here). Going through the titles I could not help smiling because some of them are really funny. So I decided to make a top 10 of the funniest paper titles.