swift-xdg

let dirs = try BaseDirectories(prefixAll: "my-amazing-app")
/* Get existing configuration path. */
let confPath = try dirs.findConfigFile("conf.toml")
/* If all paths are needed, just add an “s”. */
let confPaths = try dirs.findConfigFiles("conf.toml")
/* Get path for writing new config.
 * The method makes sure the parent directory exists for the file 
 *  and return the path where the file should be. */
let newConfPath = try dirs.ensureParentsForConfigFilePath("conf.toml")