Macro effect_once 

effect_once!() { /* proc-macro */ }

The effect_once! macro for creating order-independent effects that run once.

This is the recommended way to run one-time initialization effects in Telex. Unlike traditional hooks, effects created with this macro can be used conditionally or in any order.

Each macro invocation creates a unique anonymous type as the key, ensuring each call site gets its own independent effect.

Examples

Basic usage - runs once on first render:

effect_once!(cx, || {
    println!("App initialized");
    || {
        println!("App cleanup");
    }
});

Safe in conditionals:

if feature_enabled {
    effect_once!(cx, || {
        setup_feature();
        || cleanup_feature()
    });
}