This patch makes `Arc::make_unique` examine the number of weak references as well as strong references, which is required for safety. It also adds a `make_unique` method to the `Rc` type for consistency. Closes #14521.
This patch makes `Arc::make_unique` examine the number of weak references as well as strong references, which is required for safety. It also adds a `make_unique` method to the `Rc` type for consistency. Closes #14521.