Function opendal::io_util::unshared_reader

pub fn unshared_reader<R: BytesRead>(r: R) -> UnsharedReader<R>

Wraps a type and only allows unique borrowing, the main usecase is to wrap a !Sync type and implement Sync for it as this type blocks having multiple shared references to the inner value.

Safety

We must be careful when accessing inner, there must be no way to create a shared reference to it from a shared reference to an Unshared, as that would allow creating shared references on multiple threads.

As an example deriving or implementing Clone is impossible, two threads could attempt to clone a shared Unshared<T> reference which would result in accessing the same inner value concurrently.