Struct Static 

pub struct Static<T: Sync> { /* private fields */ }

A static variable intended to be initialized before main.

Expected usage

This type is designed for the “startup is single-threaded” model: it is expected that no other threads access the value until initialization has completed. After that point, the value is treated as initialized and immutable.

Concurrency

If the value is accessed concurrently while it is still being initialized (for example, from another thread during startup, including when used from a dynamic library), this is not undefined behavior, but this implementation does not wait for initialization to complete: it will panic instead.

If you need concurrent first access to be handled by blocking/spinning rather than panicking, use std::sync::OnceLock or std::sync::LazyLock (when std is available).

Panics / poisoning

If the initializer panics, the static becomes permanently poisoned: all subsequent accesses will panic, and it cannot be reset.

Trait Implementations

impl<T: Sync + Debug> Debug for Static<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Sync> Deref for Static<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T: Sync + Display> Display for Static<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Sync> Drop for Static<T>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl<T: Sync> Sync for Static<T>

SAFETY: This is safe because the static variable is either initialized and read-only, poisoned and panicing, or initializing (and will panic if multiple threads try to initialize it at the same time).