import { PipeTransform } from '@angular/core';
import { Quantity } from './quantity';
import { SystemOfUnits } from './system-of-units.service';
import { Unit } from './unit';
import * as i0 from "@angular/core";
export declare class QuantityPipe implements PipeTransform {
    private system;
    constructor(system: SystemOfUnits);
    transform(value: string | number | null | undefined, quantity?: Quantity | string, addSymbolOrUnit?: boolean | Unit | string, addSymbol?: boolean): string | undefined;
    static ɵfac: i0.ɵɵFactoryDeclaration<QuantityPipe, never>;
    static ɵpipe: i0.ɵɵPipeDeclaration<QuantityPipe, "ngQuantity", false>;
}