sso - small string optimization

I wrote this just for fun when saw article about sso in Rust. My string can store up to 23 (excluding null-terminator) 8-bit chars without calling allocator.

There are few ideas, which I not implemented:

• way to configure usage of exceptions. This can be achived with macros, but I want to try use something like traits/policies. E.g. std::string use std::char_traits, what about creating exception_traits/throw_policy/throw_strategy?

• strategy for preallocating more memory then need now I allocate exactly as much as I need. I want to do this behaviour configurable and see few ways:

  • using std::allocator_traits::allocate_at_least. Such way user can configure allocation strategy by providing custom allocator. And only in C++23
  • policy/traits as well as with exceptions. This less idiomatic for C++, but more consistent if using same way for exceptions too

And there is also one problem(mistake?). When string is small (placed on stack) I use simple O(n) algo for calculate length. That's why it can return wrong length if string contains null-terminator inside. This can be fixed by occupying one byte for store length.

BUILD

cmake -S [test | sso] -B build/
cmake --build build/ -j