I'm not claiming that C++ level of complexity is necessary, only that it is a widely known language with a lot of features that exist solely to enable this one

I'm not claiming that C++ level of complexity is necessary, only that it is a widely known language with a lot of features that exist solely to enable this one thing. Rust can do this with less complexity by embracing choices that, while conceptually simple, are very unorthodox and unintuitive, such as everything being a move rather than a copy with few exceptions (whereas in pretty much every other PL it has always been the other way around, if move semantics is supported at all).