/**
 * Returns first index of the string that is not whitespace.
 * If string is empty or contains only whitespaces, returns -1
 */
export declare function firstNonWhitespaceIndex(str: string): number;
/**
 * Returns last index of the string that is not whitespace.
 * If string is empty or contains only whitespaces, returns -1
 */
export declare function lastNonWhitespaceIndex(str: string, startIndex?: number): number;