/**
 * @param value The value being checked.
 * @return True if the value is a number and is positive, false otherwise.
 */
export declare function isPositive(value: number): boolean;
/**
 * Throws an `IsError` if the value is not positive.
 *
 * @param value The value being checked.
 * @param field The name of the field being checked.
 * @param code The application / module code assigned to this error.
 * @throws {@link IsError} if the value is not a number instance.
 */
export declare function isPositiveError(value: any, field: string, code?: string): void;