Tag Archive for: constexpr

Posts

constexpr

constexpr and consteval Functions in C++20

February 4, 2022

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With C++20, constexpr became way more powerful. Additionally, we have consteval functions in C++20…

constexpr

constexpr Functions

January 26, 2022

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Today, I continue my story about programming at compile time. After template metaprogramming, the type-traits…

TimelineCpp20CoreLanguage

constexpr std::vector and std::string in C++20

September 16, 2020

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Probably the most viral keyword in modern C++ is constexpr. With C++20, we have a constexpr std::vector…

TimelineCpp20CoreLanguage

volatile and Other Small Improvements in C++20

August 17, 2020

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Today, I complete my tour through the C++20 core language features with a few small improvements. One…

TimelineCpp20Core

C++ 20: The Core Language

October 27, 2019

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My last post C++20: The Big Four started with an overview of concepts, ranges, coroutines, and modules.…

constexpr

C++ Core Guidelines: Programming at Compile Time with constexpr

February 1, 2019

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My mini-series about programming at compile time started with template metaprogramming, continued with…

CharakteristikeImmutableDataEng

Immutable Data

January 28, 2017

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A key to purely functional languages is that their data are immutable. Therefore, assignments such as…

constexpr11

constexpr Functions

November 15, 2016

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constexpr functions are functions that can be executed at compile time. Sounds not so thrilling. But…

userdefinedTypes

constexpr – Variables and Objects

November 13, 2016

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If you declare a variable as constexpr the compiler will evaluate them at compile time. This holds not…

userdefinedLiteralsConstexprResult

Constant Expressions with constexpr

November 11, 2016

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You can define with the keyword constexpr an expression that can be evaluated at compile time. constexpr…

Latest news

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 […]