/** A function that returns a new or existing instance. */
export type Factory<T> = () => T;
/**
 * A generic dependency‐injection container.
 *  - clear() clears all registered factories.
 *  - unregister() removes a factory by key.
 *  - register() binds a key to a Factory<T>
 *  - registerNonReplaceable() binds a key to a Factory<T> and throws if already registered
 *  - get() retrieves T by key and throws if none registered
 *  - isRegistered() checks if a factory is registered for key
 *  - getKeys() returns all registered keys
 */
export interface Container {
    /** Clear all registered factories. */
    clear(): void;
    /** Unregister a factory by `key`. */
    unregister(key: PropertyKey): void;
    /** Bind a factory function to `key`. */
    register<T>(key: PropertyKey, factory: Factory<T>): void;
    /** Bind a factory function to `key`. Throws if already registered. */
    registerNonReplaceable<T>(key: PropertyKey, factory: Factory<T>): void;
    /** Retrieve an instance by `key`. Throws if none registered. */
    get<T>(key: PropertyKey): T;
    /** Check if a factory is registered for `key`. */
    isRegistered(key: PropertyKey): boolean;
    /** Get all registered keys. */
    getKeys(): PropertyKey[];
}