/// <reference types="node" />
export type MustBeNullable<T> = null extends T ? T : undefined extends T ? T : never;
export declare class Validate {
    static mail(mail: string): boolean;
    static uuid(uuid: string): boolean;
    static mac(address: string): boolean;
    static hexColor(color: string): boolean;
    static isString(value: unknown): value is string;
    static isNumber(value: unknown): value is number;
    static isFunction(value: unknown): value is Function;
    static isObject(value: unknown): value is object;
    static isNull(value: unknown): value is null;
    static isUndefined(value: unknown): value is undefined;
    static isDefinedNotNull<T>(value: unknown): value is NonNullable<MustBeNullable<T>>;
    static isBoolean(value: unknown): value is boolean;
    static isRegExp(value: unknown): value is RegExp;
    static isError(value: unknown): value is Error;
    static isDate(value: unknown, acceptTimestamp?: boolean): value is Date;
    static isBuffer(value: unknown): value is Buffer;
    static isSymbol(value: unknown): value is symbol;
    static implementsTKeys<T>(obj: unknown, keys: Array<keyof T>): obj is T;
    /**
     * Return a boolean depending on the string . ("true", "y", "yes", "oui", "on" return true, else it's return false)
     * @param str -the string
     * @param strict - return null instead of false if not in list
     */
    static stringToBoolean(str: string, strict?: boolean): boolean | null;
}