/**
 * @packageDocumentation
 * @module Utility
 */
import { MonoTypeOperatorFunction, Subscribable } from 'rxjs';
import { SupportedWeights } from '../types/weight';
/**
 * Returns an Observable that converts the source value through [[Weights]] conversion
 *
 * @category Conversion
 *
 * @typeParam I String or [[Weights]] value for the input value
 * @typeParam O String or [[Weights]] value for the output value
 *
 * @param fromWeight The weight type of the source value
 * @param toWeight The weight type of the output value
 * @param precision The number of decimal places to return, default is `2`
 *
 * @example
 * Convert Grams to Kilograms
 * ```ts
 * const source$ = from([10, 5, 100]);
 *
 * source$.pipe(weight(Weights.GRAMS, Weights.KILOGRAMS)).subscribe()
 * ```
 * Output: `0.01, 0.05, 0.1`
 *
 * @example
 * Convert Kilograms to Stone with a precision of `1`
 * ```ts
 * const source$ = from([10, 5, 100]);
 *
 * source$.pipe(weight('st', 'kg', 1)).subscribe()
 * ```
 * Output: `63.5, 31.8, 635`
 *
 * @returns Observable that emits a number that is the `from` [[Weights]] converted to the `to` [[Weights]]
 */
export declare function weight<I extends SupportedWeights, O extends SupportedWeights>(fromWeight: Subscribable<I> | I, toWeight: Subscribable<O> | O, precision?: Subscribable<number> | number): MonoTypeOperatorFunction<number>;