Function read_or_create_default 

pub fn read_or_create_default<P, T>(path: P) -> Result<T, Error>
where
    P: AsRef<Path>,
    T: DeserializeOwned + Default + Serialize,

Read config from a TOML, JSON, or JSONC file, creating the file with T::default() when it does not already exist.

use cloudiful_config::read_or_create_default;
use serde::{Deserialize, Serialize};

#[derive(Default, Deserialize, Serialize)]
struct AppConfig {
    port: u16,
}

let path = std::env::temp_dir().join("config-crate-read-or-create.toml");
let _config: AppConfig = read_or_create_default(&path).unwrap();