export declare class EnvParser {
    /**
     * Cache Map for environment variables to speed up retrieval due to system calls being slower than retrieving from memory.
     * Populated in the following scenarios:
     * - When {@link Config.refreshEnvCache} is called
     * - When {@link Config.setEnvValue} is called
     */
    private static envCache;
    /**
     * Clears the environment variable cache and updates the cache with the most up-to-date environment variables
     */
    static refreshCache(): void;
    /**
     * Removes all elements from the cache.
     */
    static clearCache(): void;
    /**
     * Sets a new value to an environment variable and writes-through the value to the cache.
     * @param key Key of the environment variable.
     * @param value The value to set the environment variable to.
     */
    static setValue(key: string, value: string): void;
    /**
     * Deletes an environment variable and removes it from the cache.
     * @param key Key or name of the environment variable.
     */
    static deleteValue(key: string): void;
    /**
     * Returns the value corresponding the to environment variable with name {@link key} in the environment variables.
     * Checks the {@link envCache} first and then process.env if there is a cache miss. Will lazy load the value into
     * the in-memory cache if there is a miss. Caches undefined environment variables as well.
     * @param key Key of the environment variable.
     * @returns The value corresponding the to environment variable with name {@link key} in the environment variables.
     */
    private static getValue;
    /**
     * Gets the specified environment variable and returns it as a plain string with no type conversions.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable.
     * @throws {UndefinedEnvVarError} Error thrown if the environment variable is not defined.
     */
    static getString(key: string): string;
    /**
     * Gets the specified environment variable and returns it as a number.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a number.
     */
    static getNumber(key: string): number;
    /**
     * Gets the specified environment variable and returns it as a boolean.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a boolean.
     */
    static getBoolean(key: string): boolean;
    /**
     * Gets the specified environment variable and returns it as a date.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a date.
     */
    static getDate(key: string): Date;
    /**
     * Gets the specified environment variable and returns it as a RegExp.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a RegExp.
     */
    static getRegExp(key: string): RegExp;
    /**
     * Gets the specified environment variable and returns it as an object.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as an object.
     */
    static getObject(key: string): object;
    /**
     * Gets the specified environment variable and returns it as an Array.
     * If the type is ommitted each element will default to type string when conversion occurs.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as an Array.
     */
    static getArray<T>(key: string, type?: string): Array<T>;
    /**
     * Gets the specified environment variable and returns it as a Set.
     * If the type is ommitted each element will default to string when conversion occurs.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a Set.
     */
    static getSet<T>(key: string, type?: string): Set<T>;
    /**
     * Gets the specified environment variable and returns it as a Map.
     * If the keyType and valueType are ommitted the keys and will default to type string when conversion occurs.
     * @param key The name of the environment variable.
     * @returns The value of the environment variable as a Map.
     */
    static getMap<K, V>(key: string, keyType?: string, valueType?: string): Map<K, V>;
}
export default EnvParser;