Crate generational_box

Generational Box

Generational Box is a runtime for Rust that allows any static type to implement Copy. It can be combined with a global runtime to create an ergonomic state solution like dioxus-signals. This crate doesn’t have any unsafe code.

Three main types manage state in Generational Box:

• Store: Handles recycling generational boxes that have been dropped. Your application should have one store or one store per thread.
• Owner: Handles dropping generational boxes. The owner acts like a runtime lifetime guard. Any states that you create with an owner will be dropped when that owner is dropped.
• GenerationalBox: The core Copy state type. The generational box will be dropped when the owner is dropped.

Example:

use generational_box::{UnsyncStorage, AnyStorage};

// Create an owner for some state for a scope
let owner = UnsyncStorage::owner();

// Create some non-copy data, move it into a owner, and work with copy data
let data: String = "hello world".to_string();
let key = owner.insert(data);

// The generational box can be read from and written to like a RefCell
let value = key.read();
assert_eq!(*value, "hello world");

How it works

Internally, generational-box creates an arena of generational RefCells that are recycled when the owner is dropped. You can think of the cells as something like &'static RefCell<Box<dyn Any>> with a generational check to make recycling a cell easier to debug. Then GenerationalBoxes are Copy because the &'static pointer is Copy.

Structs

• AlreadyBorrowedError
  An error that can occur when trying to borrow a value mutably that has already been borrowed immutably.
• AlreadyBorrowedMutError
  An error that can occur when trying to borrow a value that has already been borrowed mutably.
• GenerationalBox
  The core Copy state type. The generational box will be dropped when the Owner is dropped.
• GenerationalBoxId
  The type erased id of a generational box.
• GenerationalRef
  A reference to a value in a generational box.
• GenerationalRefBorrowInfo
  Information about a borrow.
• GenerationalRefMut
  A mutable reference to a value in a generational box.
• GenerationalRefMutBorrowInfo
  Information about a mutable borrow.
• MemoryLocation
  A dynamic memory location that can be used in a generational box.
• Owner
  Owner: Handles dropping generational boxes. The owner acts like a runtime lifetime guard. Any states that you create with an owner will be dropped when that owner is dropped.
• SyncStorage
  A thread safe storage. This is slower than the unsync storage, but allows you to share the value between threads.
• UnsyncStorage
  A unsync storage. This is the default storage type.
• ValueDroppedError
  An error that can occur when trying to use a value that has been dropped.

Enums

• BorrowError
  An error that can occur when trying to borrow a value.
• BorrowMutError
  An error that can occur when trying to borrow a value mutably.

Traits

• AnyStorage
  A trait for any storage backing type.
• Storage
  A trait for a storage backing type. (RefCell, RwLock, etc.)