Archive for category: Blog

comparisonEng

Memory and Performance Overhead of Smart Pointers

December 6, 2016

/

C++11 offers four different smart pointers. I will have a closer look in this post regarding memory and…

RessourcenmanagementEng

Careful Handling of Resources

December 5, 2016

/

The careful handling of resources - may it be, for example, memory, files, or sockets - is a key concern…

POD

Generalized Plain Old Data

December 3, 2016

/

Plain Old Data (POD) obeys the C standard layout. Therefore, you can directly apply the fast C functions…

rehashLinux

Buckets, Capacity, and Load Factor

November 29, 2016

/

The hash function maps a potentially infinite number of keys on a finite number of buckets. What is the…

hashfunction

Hash Functions

November 27, 2016

/

The hash function is responsible for the unordered associative containers' constant access time (best…

windows

Associative Containers – A simple Performance Comparison

November 25, 2016

/

Before I take a deeper look insight the interface of the hash tables - officially called unordered associative…

geordneteAssoziativeArrays

Hash Tables

November 24, 2016

/

We missed the hash table in C++ for a long time. They promise to have constant access time. C++11 has…

ContainerVersusElement

Type-Traits: Performance Matters

November 21, 2016

/

If you look carefully, you see type-traits have a big optimization potential. The type-traits support…

constexpr11

constexpr Functions

November 15, 2016

/

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

userdefinedTypes

constexpr – Variables and Objects

November 13, 2016

/

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

Latest news

Data-Parallel Types: simd_maskJuly 14, 2025 - 9:16 am
Thanks to simd_mask, conditional execution of operations on data-parallel types is possible. Unfortunately, in my last article, Data-Parallel Types – A First Example, I forgot to introduce one of the new library functions. I will make up for that in this article. Where Expression The new keyword where creates a so-called where expression. This allows […]
Data-Parallel Types – A First ExampleJune 25, 2025 - 4:01 pm
After providing a theoretical introduction to the new C++ 26 feature in my last article, “Data-Parallel Types (SIMD),” I would like to follow up today with a practical example. The following introductory example is from the experimental implementation of the SIMD library. This functionality has been fully adopted in the C++ 26 draft under the […]
Data-Parallel Types (SIMD)June 16, 2025 - 10:24 am
The data-parallel types (SIMD) library provides data-parallel types and operations on them. Today, I want to take a closer look at this. Before diving into the new library, I would like to take a moment to discuss SIMD. SIMD Vectorization refers to the SIMD (Single Instruction, Multiple Data) extensions of a modern processor’s instruction set. […]
Read-copy-update (RCU)June 2, 2025 - 9:54 am
Read-copy-update is strong in multithreading environments where a data structure is read almost exclusively but rarely written. First of all, what is RCU? The excellent Wikipedia page on Read-copy-update provides a good introduction: In computer science, read-copy-update (RCU) is a synchronization mechanism that avoids the use of lock primitives while multiple threads concurrently read and […]
atomic<shared_ptr<>> by Oliver SchädlichMay 19, 2025 - 9:11 am
This blog article is an experiment. A few days ago, I received the following email (translated from German) from Oliver Schädlich (oliver.schaedlich@gmail.com). If, as I hope, this article sparks a discussion, I will be happy to summarize it in my last article. Please send an email to: Rainer.Grimm@ModernesCpp.de. I just read your latest article on […]
Hazard Pointers in C++26May 5, 2025 - 11:12 am
Hazard pointers provide garbage collection in C++ and solve the ABA problem. First of all. What is a hazard pointer? Proposal P2530R3 gives a nice explanation: A hazard pointer is a single-writer multi-reader pointer that can be owned by at most one thread at any time. Only the owner of the hazard pointer can set […]