In the meanwhile, how is C++ lifetime profile doing, is it useable yet?
I know C++ pretty well, but I'd pick Rust (or Zig) for my next project.
Declaring a method const tells the compiler that that method won’t change the object.
Declaring something constexpr tells the compiler that if its arguments are known at compile time then it will always return the same result and may be a candidate for “invocation” at compile time.
The fact that the keywords both contain the string “const” is a consequence of the English language.
As for inference, maybe in the example, although in most code bases with binary libraries it would be useless anyway.