import * as express from 'express';
import { ExpressInstrumentationConfig } from './types';
import { InstrumentationBase } from '@opentelemetry/instrumentation';
/**
 * This symbol is used to mark express layer as being already instrumented
 * since its possible to use a given layer multiple times (ex: middlewares)
 */
export declare const kLayerPatched: unique symbol;
/** Express instrumentation for OpenTelemetry */
export declare class ExpressInstrumentation extends InstrumentationBase<typeof express> {
    constructor(config?: ExpressInstrumentationConfig);
    init(): any[];
    /**
     * Get the patch for Router.route function
     */
    private _getRoutePatch;
    /**
     * Get the patch for Router.use function
     */
    private _getRouterUsePatch;
    /**
     * Get the patch for Application.use function
     */
    private _getAppUsePatch;
    /** Patch each express layer to create span and propagate context */
    private _applyPatch;
}