C++ - Reddit on Telegram: “What I Learned About [no_unique

Post #24659 26 Jan 10, 2026, 15:46 UTC

What I Learned About [no_unique_address] and Padding Reuse in C++

https://nekrozqliphort.github.io/posts/no-unique-address/

Hey everyone! It’s been a while since my last write-up. I recently spent some time looking into [[no_unique_address]], specifically whether it reliably saves space by reusing padding bytes. In a few cases, it didn’t behave quite as I expected, so I decided to dig a bit deeper.

This post is a short investigation into when padding reuse does and doesn't happen, with some concrete layout examples and ABI-level discussion.

Any feedback or corrections would be greatly appreciated!

https://redd.it/1q95vk1
@r_cpp

Ryan Chung Learner’s Notes: Alignment and padding - What does [[no_unique_address]] do? Problem Statement Let’s start with a small, innocent-looking example: ```cpp struct Foo { long long foo_val; bool foo_val2; };

Open in Telegram All posts from @r_cpp