Archive for category: C++20

C++20: Module Support of the Big Three

October 16, 2023

I have written almost 100 posts about C++20 in the last four years, but I'm not done. This post continues…

Improved Iterators with Ranges

June 9, 2022

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There are more reasons to prefer ranges library above the classical Standard Template Library. The ranges…

Sentinels and Concepts with Ranges Algorithms

May 31, 2022

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The ranges library in C++20 supports sentinels. Sentinels stand for the end of a range and can be regarded…

Projections with Ranges

May 25, 2022

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The algorithms of the ranges library are lazy, can work directly on the container, and can easily be…

The Ranges Library in C++20: More Details

May 19, 2022

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Working with the Standard Template Library (STL) is much more comfortable and powerful thanks to the…

TimelineCpp20Concepts

Check Types with Concepts

May 12, 2022

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Concepts are a powerful and elegant tool to check at compile time if a type fulfills. Thanks to static_assert,…

TimelineCpp20Concepts

Check Types with Concepts – The Motivation

May 5, 2022

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static_assert allows you to check at compile time if a type T fulfills the Concept: static_assert(Concept<T>). Before…

TimelineCpp20Concepts

Using Requires Expression in C++20 as a Standalone Feature

April 27, 2022

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In my last post "Defining Concepts with Requires Expressions", I exemplified how you can use requires…

TimelineCpp20Concepts

Defining Concepts with Requires Expressions

April 20, 2022

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In my last post, "Define Concepts", I defined the concepts Integral, SignedIntegral, and UnsigendIntegral…

TimelineCpp20Concepts

Define Concepts

April 12, 2022

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There are two ways to define a concept: You can combine existing concepts and compile-time predicates,…

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C++26 Core Language: Small ImprovementsNovember 4, 2024 - 8:34 am
There are more small improvements in the C++26 language, which you should know. static_assert extension First, here’s the syntax of static_assert in C++11: static_assert(compile time predicate, unevaluated string) With C++26, the string can be a user-defined type having the following properties: static_assert can now be used with a format string. Here’s a nice example from […]
Placeholders and Extended Character SetOctober 28, 2024 - 10:19 am
Placeholders are a nice way to highlight variables that are no longer needed. Additionally, the character set of C++26 will be extended. Placeholders Structured bindings are a C++17 feature that allows you to bind multiple variables to the elements of a structured object. The following program demonstrates using tuples and structured bindings to return and […]
Contracts in C++26October 21, 2024 - 9:54 am
Contracts allow you to specify preconditions, postconditions, and invariants for functions. Contracts should already be part of C++20 but were removed in the standard meeting in Cologne. Here is what Herb Sutter said about contracts on Sutter’s Mill: “contracts is the most impactful feature of C++20 so far, and arguably the most impactful feature we […]
Reflection in C++26: Determine the LayoutOctober 14, 2024 - 9:42 am
Thanks to reflection, you can determine the layout of types. My examples are based on the reflection proposal P2996R5. Class Layout The following program determines the class layout of a few members. // classLayout.cpp #include <experimental/meta> #include <iostream> #include <utility> #include <vector> #include <array> struct member_descriptor { std::size_t offset; std::size_t size; bool operator==(member_descriptor const&) const […]
Reflection in C++26: Metafunctions for Enums and ClassesOctober 7, 2024 - 1:53 pm
Today, I continue my journey through reflection in C++26 and play with enums and classes. The names of the metafunctions to access an Enum or a Class member are often identical. Access the Members of an Enum The following program is based on one by Daveed Vandevoorde. Daveed is one of the fathers of reflection, […]
Reflection in C++26: MetafunctionsSeptember 30, 2024 - 10:14 am
Reflection offers many metafunctions that run at compile time. The metafunctions are declared as consteval. consteval creates a so-called immediate function. Each invocation of an immediate function creates a compile-time constant. To say it more directly. A consteval (immediate) function is executed at compile-time. Read more about consteval and constinit in my previous post: Two […]