import { OnDestroy, TemplateRef, ViewContainerRef, ViewRef } from '@angular/core';
export declare type TemplateDef = any;
export declare const enum KeepAliveFlags {
    Detached = 0,
    Attached = 1
}
export declare class ViewRefAttachable {
    viewRef: ViewRef;
    flag: KeepAliveFlags;
    viewContainerRef: ViewContainerRef;
    get attached(): boolean;
    get detached(): boolean;
    constructor(viewRef: ViewRef);
    attachToViewContainerRef(viewContainer: ViewContainerRef): void;
    detachFromViewContainerRef(): void;
    destroy(): void;
}
export declare class KeepAliveConfig {
    limit: number;
}
export declare class KeepAliveGC {
    private config;
    constructor(config: KeepAliveConfig);
    collect(viewRefs: Map<TemplateDef, ViewRefAttachable>): void;
}
export declare class KeepAliveViewRefs implements OnDestroy {
    private gc;
    private viewRefs;
    constructor(gc: KeepAliveGC);
    add(templateRef: TemplateRef<any>, viewRef: ViewRef): void;
    has(templateRef: TemplateRef<any>): boolean;
    get(templateRef: TemplateRef<any>): ViewRefAttachable;
    delete(templateRef: TemplateRef<any>): boolean;
    reattach(templateRef: TemplateRef<any>): void;
    ngOnDestroy(): void;
    collect(): void;
    forEach(fn: (v: ViewRefAttachable) => void): void;
    private getTemplateDef;
}
export declare class KeepAliveManager {
    private viewRefs;
    static patched: symbol;
    constructor(viewRefs: KeepAliveViewRefs);
    attach(viewContainerRef: ViewContainerRef, templateRef: TemplateRef<any>): void;
    detach(viewContainerRef: ViewContainerRef, templateRef: TemplateRef<any>): void;
    private patchClear;
}
export declare class KeepAliveDirective implements OnDestroy {
    private manager;
    private viewContainerRef;
    private templateRef;
    constructor(manager: KeepAliveManager, viewContainerRef: ViewContainerRef, templateRef: TemplateRef<any>);
    ngOnDestroy(): void;
}