import { Operator } from '../Seq';
/**
 * Returns a sequence to be enumerated only while the condition is matched.
 *
 * ```typescript
 * const result = range(1,10).pipe(
 *   takeWhile(i => i < 5)
 * ).toArray()
 *
 * //result: [1,2,3,4]
 * ```
 *
 * @param predicate Condition.
 * @typeParam T Source element type.
 * @returns Operator function.
 * @category Operators
 */
export declare const takeWhile: <T>(predicate: (arg: T) => boolean) => Operator<T, T>;