//! How can we define some default values? You can use `Default`:
//!
//! ```
-//! use std::default::Default;
-//!
//! #[derive(Default)]
//! struct SomeOptions {
//! foo: i32,
//! If you have your own type, you need to implement `Default` yourself:
//!
//! ```
-//! use std::default::Default;
-//!
//! enum Kind {
//! A,
//! B,
//! If you want to override a particular option, but still retain the other defaults:
//!
//! ```
-//! # use std::default::Default;
//! # #[derive(Default)]
//! # struct SomeOptions {
//! # foo: i32,
/// Using built-in default values:
///
/// ```
- /// use std::default::Default;
- ///
/// let i: i8 = Default::default();
/// let (x, y): (Option<String>, f64) = Default::default();
/// let (a, b, (c, d)): (i32, u32, (bool, bool)) = Default::default();
/// Making your own:
///
/// ```
- /// use std::default::Default;
- ///
/// enum Kind {
/// A,
/// B,