C++ 中文周刊 第125期

资讯

标准委员会动态/ide/编译器信息放在这里

编译器信息最新动态推荐关注hellogcc公众号 本周更新 2023-08-02 第213期

文章

• • RocksDB 源码阅读系列[1]

写的不错

• • Understanding Ranges Views and View Adaptors Objects in C++20/C++23 [2]

#include <ranges>
#include <vector>
#include <iostream>

int main() {
    std::vector<int> r = {1, 2, 3, 4, 5};
    auto reversed = r | std::views::reverse;
    for (auto i : reversed)
        std::cout << i << " ";
        
    // same as:
    //for (auto i : r | std::views::reverse)
        //std::cout << i << " ";
    
    std::cout << '\n';
    std::ranges::reverse_view rv(r);
    for (auto i : rv)
        std::cout << i << " ";
}

探讨这玩意是怎么实现的

• • soagen: A Structure-of-Arrays generator for C++ [3]

帮你把结构体组成的数组这种行存转换为数组结构体模式列存

是代码帮你生成tuple。有点繁琐

• • Did you know that C++26 added user-generated static_assert messages?[4]

static_assert(false, std::string_view{"message"});

既然能string_view 也就可以fmt

• • Inside STL: The pair and the compressed pair[5]

没啥说的。能省点空间

template<typename T1, typename T2>
struct compressed_pair {
    [[no_unique_address]] T1 first;
    [[no_unique_address]] T2 second;
};

• • Inside STL: The string[6]

介绍string对小字符串做的优化，类似clang::string的实现分析

• • A Gentle Introduction to LLVM IR[7]

光速入门

• • MySQL · 源码剖析 · LF_HASH无锁实现[8]

亮点还是扩容不需要迁移，很有意思

• • Misinterpreting the misleadingly-named STATUS_STACK_BUFFER_OVERRUN[9]

看不懂

视频

meeting cpp推荐了十个，我把我感兴趣的列一下

Daniel Withopf - Compile-time Is the New Constexpr: Leveraging Compile-time Sparsity for Vectors and Matrices[10]

大概意思是利用constexpr算某些场景比elgen快

Filipp Gelman - What I learned From Sockets[11]

讲了一堆设计。没有代码，听个乐

开源项目需要人手

• • asteria[12] 一个脚本语言，可嵌入，长期找人，希望胖友们帮帮忙，也可以加群384042845和作者对线
• • Unilang[13] deepin的一个通用编程语言，点子有点意思，也缺人，感兴趣的可以github讨论区或者deepin论坛看一看。这里也挂着长期推荐了
• • gcc-mcf[14] 懂的都懂

新项目介绍/版本更新

• • battery-embed[15]

std::embed没有之前能对付用的替代品

• • https://tavianator.com/2023/bfs_3.0.html1

这哥们写了个find，和bfs一个原理，并发宽度优先遍历，find默认是dfs。

实际效果比find快百倍。很有意思。可以装一个玩玩

• • https://github.com/jll63/yomm2/blob/master/reference/virtual_ptr.md

一个fat pointer实现

• • https://github.com/DeveloperPaul123/thread-pool/tree/0.6.2

一个实现了work steal的线程池

关于 work steal，道理都懂，可能还需要看看https://www.youtube.com/watch?v=iLHNF7SgVN4&ab_channel=CppCon 了解下

工作招聘

有没有可以远程的工作可以推荐给我，我也快失业了

API Design

最近群里收集了一些想要讨论的点子，大家比较关注API设计，我这里把一些资料放在这里。可能后面会做个视频

https://www.youtube.com/watch?v=zL-vn_pGGgY&ab_channel=CppCon

https://www.youtube.com/watch?v=2UmDvg5xv1U&ab_channel=CppNow

https://www.acodersjourney.com/top-25-cplusplus-api-design-mistakes-and-how-to-avoid-them/

本文永久链接[16]

如果有疑问评论最好在上面链接到评论区里评论，这样方便搜索，微信公众号有点封闭/知乎吞评论

引用链接

[1] RocksDB 源码阅读系列: https://zhuanlan.zhihu.com/p/646776844 [2] Understanding Ranges Views and View Adaptors Objects in C++20/C++23 : https://www.cppstories.com/2023/cpp20-understanding-views-impl/ [3] soagen: A Structure-of-Arrays generator for C++ : https://marzer.github.io/soagen/ [4] Did you know that C++26 added user-generated static_assert messages?: https://github.com/tip-of-the-week/cpp [5] Inside STL: The pair and the compressed pair: https://devblogs.microsoft.com/oldnewthing/20230801-00/?p=108509 [6] Inside STL: The string: https://devblogs.microsoft.com/oldnewthing/20230803-00/?p=108532 [7] A Gentle Introduction to LLVM IR: https://mcyoung.xyz/2023/08/01/llvm-ir/ [8] MySQL · 源码剖析 · LF_HASH无锁实现: https://zhuanlan.zhihu.com/p/452849776 [9] Misinterpreting the misleadingly-named STATUS_STACK_BUFFER_OVERRUN: https://devblogs.microsoft.com/oldnewthing/20230731-00/?p=108505 [10] Daniel Withopf - Compile-time Is the New Constexpr: Leveraging Compile-time Sparsity for Vectors and Matrices: https://www.youtube.com/watch?v=PybIAMIZrVE&ab_channel=CppNow [11] Filipp Gelman - What I learned From Sockets: https://www.youtube.com/watch?v=DA6AGCadH60&ab_channel=ACCUConference [12] asteria: https://github.com/lhmouse/asteria [13] Unilang: https://github.com/linuxdeepin/unilang [14] gcc-mcf: https://gcc-mcf.lhmouse.com/ [15] battery-embed: https://github.com/batterycenter/embed [16] 本文永久链接: https://wanghenshui.github.io/cppweeklynews/posts/125.html