Singlyton

Safe, single-threaded global state in Rust.

Debug assertions are present to ensure:

• Borrow checking (see RefCell)
• Thread safety (two threads cannot access the same singleton)
• Sound usage of uninitialized memory

Why?

Single-threaded global state is a bit of a boogeyman in Rust:

• static mut is heavily discouraged due to its easy ability to cause UB through aliasing.
• Thread locals can be slow for performance critical contexts, are nonsense to use in a single-threaded environment, and may not be available on all platforms
• Working around Rust's thread-safety mechanisms in single-threaded contexts can be ugly, annoying and unnecessary

Usage

First, add singlyton as a dependency of your project in your Cargo.toml file:

toml [dependencies] singlyton = "*"

Singleton

```rust use singlyton::Singleton;

static SINGLETON: Singleton<&'static str> = Singleton::new("Hello"); debugasserteq!(*SINGLETON.get(), "Hello");

SINGLETON.replace("Test"); debugasserteq!(*SINGLETON.get(), "Test");

SINGLETON.get_mut() = "Test 2"; debug_assert_eq!(SINGLETON.get(), "Test 2"); ```

SingletonUninit

```rust use singlyton::SingletonUninit;

static SINGLETON: SingletonUninit = SingletonUninit::uninit();

SINGLETON.init("Hello".tostring()); debugasserteq!(SINGLETON.get().asstr(), "Hello");

SINGLETON.replace("Test".tostring()); debugasserteq!(SINGLETON.get().asstr(), "Test");

*SINGLETON.getmut() = "Test 2".tostring(); debugasserteq!(SINGLETON.get().as_str(), "Test 2"); ```