import type { $Record } from '../object/types';
import type { Numeric } from '../types/index';
import { $BaseConverter } from './base';
import type { $MassUnit, FormatToOptions } from './types';
/**
 * @class MassConverter
 * @description Handles conversions with smart `.to()`, `.toAll()`, and `.formatTo()`.
 */
export declare class $Mass extends $BaseConverter<$MassUnit> {
    #private;
    /**
     * Convert mass value to other mass units
     * @param value Number or numeric string value to convert.
     * @param unit Base mass unit for the provided value.
     */
    constructor(value: Numeric, unit: $MassUnit);
    /**
     * @instance Converts to target mass unit.
     * @param target Target mass unit.
     */
    to(target: $MassUnit): number;
    /**
     * @instance Converts to all mass units at once.
     * @returns Object with all unit conversions.
     */
    toAll(): $Record<$MassUnit, number>;
    /**
     * @instance Formats the converted value and unit.
     * @param target Target unit to format to.
     * @param options Formatting options.
     * @returns Formatted string like "5kg", "5.25 kilograms", or "5e+3 gram".
     */
    formatTo(target: $MassUnit, options?: FormatToOptions): string;
}