Macro instances

macro_rules! instances {
    () => { ... };
    ($(#[$attr:meta])* $vis:vis static $NAME:ident: $t:ty = $e:expr; $($rest:tt)*) => { ... };
    ($(#[$attr:meta])* $vis:vis static $NAME:ident: $t:ty = $e:expr) => { ... };
}

Declares that all static variables within the macro body define unique families of linked objects.

Each .get() on an included static variable returns a new linked object instance, with all instances obtained from the same static variable being part of the same family.

Example

linked::instances!(static TOKEN_CACHE: TokenCache = TokenCache::with_capacity(1000));

fn do_something() {
    // `.get()` returns a unique linked instance on every call,
    // so you are expected to reuse the instance for efficiency.
    let token_cache = TOKEN_CACHE.get();

    let token1 = token_cache.get_token();
    let token2 = token_cache.get_token();
}

Dynamic family definition

If you do not know in advance how many object families are necessary and need to define them at runtime, consider using these alternatives:

• linked::InstancePerThread<T>
• linked::InstancePerThreadSync<T> (if T: Sync)
• linked::Family<T>