/** @import { OperationHandler } from "./operation-handler" */
/**
 * An internal symbol, used to prevent direct implementation of interfaces.
 *
 * @hidden
 * @internal
 */
declare const isHandlerStartOperationResultSymbol: unique symbol;
/**
 * The return type from the {@link OperationHandler.start} method.
 *
 * Use either {@link HandlerStartOperationResult.sync} or {@link HandlerStartOperationResult.async}
 * to create a result object. Do not implement this interface directly.
 *
 * @experimental
 */
export type HandlerStartOperationResult<T = unknown> = HandlerStartOperationResultSync<T> | HandlerStartOperationResultAsync;
/**
 * The return type from the {@link OperationHandler.start} method.
 *
 * Use either {@link HandlerStartOperationResult.sync} or {@link HandlerStartOperationResult.async}
 * to create a result object. Do not implement this interface directly.
 *
 * @experimental
 */
export declare const HandlerStartOperationResult: {
    /**
     * Create a result that indicates that an operation has been accepted and will complete asynchronously.
     */
    async(token: string): HandlerStartOperationResultAsync;
    /**
     * Create a result that indicates that an operation completed successfully.
     */
    sync<T>(value: T): HandlerStartOperationResultSync<T>;
    [Symbol.hasInstance]: (this: any, value: object) => boolean;
};
/**
 * A result that indicates that an operation completed successfully.
 *
 * Use {@link HandlerStartOperationResult.sync} to create a sync result object.
 * Do not implement this interface directly.
 *
 * @example
 * ```typescript
 *   return HandlerStartOperationResult.sync(42);
 * ```
 *
 * @experimental
 */
export interface HandlerStartOperationResultSync<T = unknown> {
    /**
     * Indicate whether the operation completed synchronously (false) or will complete
     * asynchronously (true).
     */
    isAsync: false;
    /**
     * The return value of the operation.
     */
    value: T;
    /**
     * Prevents direct implementation of this interface.
     *
     * @hidden
     * @internal
     */
    [isHandlerStartOperationResultSymbol]: true;
}
/**
 * A result that indicates that an operation has been accepted and will complete asynchronously.
 *
 * Use {@link HandlerStartOperationResult.async} to create an async result object.
 * Do not implement this interface directly.
 *
 * @example
 * ```typescript
 *   return HandlerStartOperationResult.async("unique token");
 * ```
 *
 * @experimental
 */
export interface HandlerStartOperationResultAsync {
    /**
     * Indicate whether the operation completed synchronously (false) or will complete
     * asynchronously (true).
     */
    isAsync: true;
    /**
     * A token to identify the operation in followup handler methods such as {@link OperationHandler.getResult}
     * and {@link OperationHandler.cancel}.
     */
    token: string;
    /**
     * Prevents direct implementation of this interface.
     *
     * @hidden
     * @internal
     */
    [isHandlerStartOperationResultSymbol]: true;
}
export {};