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//! Types for the documentation examples.
//!
//! # Features
//!
//! This module is only exported with the "fmt" feature, and the nightly compiler,
//! because at the time of writing these docs (2021-08-XX) mutable references in const fn
//! require the unstable
//! [`const_mut_refs`](https://github.com/rust-lang/rust/issues/57349) feature.

use crate::{impl_fmt, try_, Error, Formatter, PWrapper};

/// An example struct which implements const debug formatting.
#[derive(Debug, Copy, Clone)]
pub struct Point3 {
    ///
    pub x: u32,
    ///
    pub y: u32,
    ///
    pub z: u32,
}

impl_fmt! {
    impl Point3;

    ///
    pub const fn const_debug_fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
        let mut f = f.debug_struct("Point3");
        try_!(PWrapper(self.x).const_debug_fmt(f.field("x")));
        try_!(PWrapper(self.y).const_debug_fmt(f.field("y")));
        try_!(PWrapper(self.z).const_debug_fmt(f.field("z")));
        f.finish()
    }

    ///
    pub const fn const_eq(&self, other: &Self) -> bool {
        self.x == other.x &&
        self.y == other.y &&
        self.z == other.z
    }
}

/// An example unit struct which implements const debug formatting.
#[derive(Debug, Copy, Clone)]
pub struct Unit;

impl_fmt! {
    impl Unit;

    ///
    pub const fn const_debug_fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
        f.debug_struct("Unit").finish()
    }

    ///
    pub const fn const_eq(&self, _other: &Self) -> bool {
        true
    }
}