I’ve done C++ on a Cortex-M0+ with 8KB of flash. Code size is a big issue. You have to disable a bunch of stuff (no exceptions, nothing that does dynamic allocation) but you can still use classes, virtual methods, templates, constexpr, etc. These are all things that are a pain to do in C and usually require a bunch of gross macros.
As a former C++ programmer now writing C, I think this only true for templates, but it if you limited to somewhat this is also fine. For constexpr it depends what you use it for. If it something expensive to compute I would just run a program at build time (caching the output) and include the result. This seems preferable to me anyhow. The same for tests.
Yeah, embedded C++ is a wildly different experience from vanilla. I've worked in large embedded C++ codebases where we couldn't use the STL and had to use homegrown containers for everything.
I wonder how Rust is stacking up (no pun intended) in the embedded game these days.
