In C++, what is the shortest way to declare a vector of vectors, where each inner std::vector's metadata fields (importantly size and pointer) have a user-chosen alignment? Ideally I'd be able to ...

In the critpath of a threaded app I've encountered a performance bottleneck. profiling indicates unexpected contention on cache lines despite what appears to be independent data access across ...

Prior to Clang 19, it was possible to write: struct alignas(8) my_struct { void* a_pointer; int a_variable; int _padding; }; However, in Clang 19, you must write: struct my_struct { ...

I'd like to understand the validity of different alignas specifier position within a plain array definition: constexpr std::size_t Required=16; alignas(Required) int iarr1[10]; // 1 int alignas(...

I have a buffer with chunks that align to the cacheline size, but have arbitrary length, let's say 100 bytes. It is clear to me that the buffer (vector) elements are aligned on cacheline borders, but ...

I'm trying to assemble information in a struct to later memcopy it to an spi buffer. This is the code I'm working with: Demo #include <cstdio> #include <cstdint> #include <cstring> /*...

The use of aligned_storage is deprecated in C++23 and suggested to be replaced with an aligned std::byte[] (see here). I have two questions about this: 1. How to align this? The document suggests to ...

I'm using SSE/AVX and I need to store aligned data. how ever, my data can be of different types. so I use a union like this union Data { bool Bools[128]; int32 Ints32[128]; int64 Ints64[...

I was wondering if someone can try to implement alignas with mmap by playing with the first parameter? If not, then can anyone try to implement alignas themselves?

why alignas(64) not aligned with 64? for example: struct alignas(32) st32 { float a; uint16_t b; uint64_t c; }; struct alignas(64) st64 { float a; uint16_t b; uint64_t c; }; ...

This must be a repeat question, but I have not found it after searching for 2 days ... I'm using MSVC with /std:c17 /std:c++17 and trying to get alignas(64) to work with arrays of doubles. The syntax ...

This is the code I usually write: alignas(16) __m128 myBuffer[8]; But maybe (since the object-array is 128*8 bit = 128 byte) I should write: alignas(128) __m128 myBuffer[8]; Or, "since the ...

I am migrating a project from CubeIDE (GCC) to the most comprehensive software development solution for Arm®-based microcontrollers uVision (ARM Compiler 5) and have a difficulty using __align keyword....

Can C++ template parameters be used to control specifiers on the class itself to minimize some code duplication? For example: I have a class that I'd like to use both in a concurrent context (and ...

Suppose I have the following simple class: struct employee{ std::string name; short salary; std::size_t age; employee(std::string name, short salary, std::size_t ...