It helps to make the code more secure, readable and maintainable. It very is necessary for us to implement the same principle in the Test Framework as well. (It also requires that the program is linked with -lstdc++exp.Before jumping into the details of this chapter of Encapsulate Selenium Page Objects, let's just understand what is the most important Object Oriented Programming Principle. This feature is highly experimental and has to be enabled by the -fcontracts option. ContractsĮven though C++ Contracts are not in the C++ standard yet (although they briefly were in N4820-see Contract Attributes), GCC 13 implements a draft of C++ Contracts. For example, certain wrong uses of std::function, std::pair, and std::make_from_tuple are now caught and an error is issued. We have made use of these new traits in the standard C++ library to detect buggy code. These traits are called std::reference_constructs_from_temporary and std::reference_converts_from_temporary. Which is incorrect because it always creates a dangling reference, because the std::string temporary is created inside the selected constructor of std::pair, and not outside it. GCC 13 supports P2255R2, which adds two new type traits to detect reference binding to a temporary. Static constexpr bool operator() (int x, int y) Traits to detect reference binding to temporary A static member function avoids the overhead because it doesn’t get the implicit object parameter. Every non-static member function needs to pass the invisible this pointer, which causes additional overhead when such a function is invoked. As the names suggest, these proposals allow the programmer to create a static function call operator and a static subscript operator. GCC 13 implements both P1169R4 - static operator() and P2589R1 - static operator. GCC offers a new option, -Winvalid-constexpr, to get a diagnostic when a function could not be invoked in a constexpr context yet even in C++23 mode.į(i) // warns by default in C++20, in C++23 only with -Winvalid-constexpr The intent is to allow functions to be marked constexpr that will later become usable in a constant expression, once other functions that they call become constexpr. In a similar vein, P2448R2 brings further constexpr relaxation: in C++23, a constexpr function’s return type or the type of its parameter does not have to be a literal type anymore, and, perhaps more importantly, a constexpr function does not necessarily need to satisfy the requirement of a core constant expression (but actually calling such a function will result in a compile-time error). Static constexpr char c = "Hello World" // OK in C++23 In C++23 (but not earlier modes), P2647R1 allows using static constexpr variables in constexpr functions: It’s become customary to relax restrictions about the usage of the constexpr keyword since its introduction in C++11. GCC 13 already implements this defect report, so the warning doesn’t trigger for other compound operations such as +=. A related defect report, CWG 2654, was recently approved, meaning that the rest of the compound assignment operators were un-deprecated as well. The change was backported to GCC 12 and 11 as well, so those versions also don’t warn for the test case above. As a consequence, bit-wise operations on volatile operands no longer warn: P2327R1 partially reverts C++20 P1152R4, which deprecated many uses of volatile. (GCC 12 rejected the example above.) De-deprecating volatile compound operations In other words, this program compiles without errors in all C++ modes with GCC 13:īecause static_assert (false) in uninstantiated templates is now accepted. The consequence is that a failing static_assert is only ill-formed at instantiation time. Traits to detect reference binding to temporary.Labels at the end of compound statements.De-deprecating volatile compound operations.This section describes the following new C++23 features: Note that C++20 and C++23 features are still experimental in GCC 13. You can use the -std=c++23 or -std=gnu++23 command-line options to enable C++23 features, and similarly for C++20 and others. The default dialect in GCC 13 is -std=gnu++17. Interesting changes in the standard C++ library that comes with GCC 13 are described in a separate blog post: New C features in GCC 13 Like the article I wrote about GCC 10 and GCC 12, this article describes only new features implemented in the C++ front end it does not discuss developments in the C++ language itself. It's also possible to try GCC 13 on and similar web pages. Red Hat Enterprise Linux (RHEL) users will get GCC 13 in the Red Hat GCC Toolset (RHEL 8 and RHEL 9). GCC 13 is already the system compiler in Fedora 38. Like every major GCC release, this version brings many additions, improvements, bug fixes, and new features. The latest major version of the GNU Compiler Collection (GCC), 13.1, was released in April 2023.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |