C++ 中文周刊 第145期
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本期文章由 黄亮Anthony HNY 赞助
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 2024-01-03 第235期
文章
现代分支预测：从学术界到工业界 https://zhuanlan.zhihu.com/p/675456587?utm_psn=1727335890022830082
看个乐呵, 了解概念对于CPU运行还是有点理解的
LLVM中指令选择的流程是啥样的？https://zhuanlan.zhihu.com/p/675543769?utm_psn=1727335764789129217
LLVM知识，学吧，都是知识，早晚碰到
数据结构】Jemalloc中的Radix Tree https://zhuanlan.zhihu.com/p/675177015?utm_psn=1727335511331631104
解析Jemalloc的关键数据结构 https://zhuanlan.zhihu.com/p/671608149?utm_psn=1727335367877697536
jemalloc最新知识，学吧
Optimizing the unoptimizable: a journey to faster C++ compile times https://vitaut.net/posts/2024/faster-cpp-compile-times/
编译很慢，怎么抓？
ftime-trace的数据可以放到浏览器的tracing里，比如 chrome://tracing/
firefox可以用这个 https://profiler.firefox.com/from-url/https%3A%2F%2Fvitaut.net%2Ffiles%2F2024-hello-before.json/marker-chart/?globalTrackOrder=0&hiddenLocalTracksByPid=65312-fwx3&thread=0&timelineType=category&v=10
我没看懂他是怎么分析出头文件的耗时的，总之，把string前向声明一下
但是这种接口编译不过
因为basic_string<char>找不到实现，怎么破？
然后这个操作就省掉了大量编译时间
Why doesn’t my code compile when I change a shared_ptr(p) to an equivalent make_shared(p)? https://devblogs.microsoft.com/oldnewthing/20240103-00/?p=109228
结构是这样的
能不能换成make_shared？不能，因为是private继承
怎么破？
c++ tip of week 反射一例
Inside STL: The deque, implementation https://devblogs.microsoft.com/oldnewthing/20230810-00/?p=108587
deque msvc实现有坑爹的地方
gcc | clang | msvc | |
|---|---|---|---|
Block size | as many as fit in 512 bytes but at least 1 element | as many as fit in 4096 bytes but at least 16 elements | power of 2 that fits in 16 bytes but at least 1 element |
Initial map size | 8 | 2 | 8 |
Map growth | 2× | 2× | 2× |
Map shrinkage | On request | On request | On request |
Initial first/last | Center | Start | Start |
Members | block** map; size_t map_size;iterator first;iterator last; | block** map;block** first_block;block** last_block;block** end_block;size_t first;size_t size; | block** map; size_t map_size;size_t first;size_t size; |
Map layout | counted array | simple_deque | counted array |
Valid range | Pair of iterators | Start and count | Start and count |
Iterator | T* current;T* current_block_begin;T* current_block_end;block** current_block; | T* current; block** current_block; | deque* parent;size_t index; |
begin()/end() | Copy first and last. | Break first and first + size into block index and offset. | Break first and first + size into block index and offset. |
Spare blocks | Aggressively pruned | Keep one on each end | Keep all |
block size太小了
windows相关
- • How to allocate address space with a custom alignment or in a custom address region https://devblogs.microsoft.com/oldnewthing/20231229-00/?p=109204
- • How do I prevent my ATL class from participating in COM aggregation? DECLARE_NOT_AGGREGATABLE didn’t work https://devblogs.microsoft.com/oldnewthing/20240101-00/?p=109214
- • The case of the vector with an impossibly large size https://devblogs.microsoft.com/oldnewthing/20240105-00/?p=109242
视频
What we've been (a)waiting for? - Hana Dusíková - Meeting C++ 2023 https://www.youtube.com/watch?v=_Q9tiEa-jG4&ab_channel=MeetingCpp
介绍协程并写了个co curl 有点意思，视频我也传B站了
https://www.bilibili.com/video/BV1NG411B7Fy/
代码在这里 https://github.com/hanickadot/co_curl
开源项目更新/新项目介绍
- • fmt10.2更新，支持duration打印 %j 还支持这么玩
- • mp-units 2.1.0 released! https://mpusz.github.io/mp-units/2.2/blog/2023/12/09/mp-units-210-released/
编译期物理计算的
- • nanobind https://nanobind.readthedocs.io/en/latest/benchmark.html 一个python binding，速度性能都不错，群友kenshin推荐
- • https://github.com/lhmouse/asteria 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753302367和作者对线
- • Unilang https://github.com/linuxdeepin/unilang 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
腾讯云开发者
