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//! General-purpose sum types.
//!
//! **[Crates.io](https://crates.io/crates/sum) │ [Repo](https://github.com/alecmocatta/sum)**
//!
//! Arbitrarily-sized product types exist in Rust in the form of [tuples](https://doc.rust-lang.org/std/primitive.tuple.html). This is a generalisation of bluss's [Either](https://docs.rs/either/1.5.0/either/enum.Either.html) type to provide **arbitrarily-sized sum types**\*.
//!
//! \* Over up to 32 types.

#![doc(html_root_url = "https://docs.rs/sum/0.1.0")]
#![allow(unused_variables, unreachable_patterns)]
#![cfg_attr(
	feature = "cargo-clippy",
	allow(renamed_and_removed_lints, type_complexity, deprecated_cfg_attr)
)]

#[cfg(feature = "serde")]
#[macro_use]
extern crate serde;

#[cfg_attr(rustfmt, rustfmt_skip)]
use std::error::Error;
#[cfg_attr(rustfmt, rustfmt_skip)]
use std::fmt::{Display, Formatter, Result};

macro_rules! impl_sum {
	(@into_inner $name:ident : $($t:ident)* : !) => (
		impl $name {
			pub fn into_inner(self) -> ! {
				match self { }
			}
		}
	);
	(@into_inner $name:ident : $($t:ident)* : $first_a:ident $($a:ident)*) => (
		impl<$first_a> $name<$first_a, $($a,)*> {
			pub fn into_inner(self) -> $first_a {
				match self {
					$($name::$t(inner) => inner,)*
				}
			}
		}
	);
	($name:ident : $($t:ident $is:ident $map:ident $get:ident)* : $first_a:tt $($a:ident)* ) => (
		#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
		#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
		pub enum $name<$($t,)*> {
			$($t($t),)*
		}
		impl<$($t,)*> $name<$($t,)*> {
			$(
			pub fn $is(&self) -> bool {
				match *self {
					$name::$t(_) => true,
					_ => false
				}
			}
			// TODO
			// pub fn $map<F,O>(self, f: F) -> $name<$(&$t,)*> where F: FnOnce($t)->O {
			// 	match self {
			// 		$name::$t(a) => $name::$t(f(a)),
			// 		$($name::$t(inner) => inner,)*
			// 	}
			// }
			pub fn $get(self) -> Option<$t> {
				match self {
					$name::$t(a) => Some(a),
					_ => None
				}
			}
			)*
			pub fn as_ref(&self) -> $name<$(&$t,)*> {
				match *self {
					$($name::$t(ref a) => $name::$t(a),)*
				}
			}
			pub fn as_mut(&mut self) -> $name<$(&mut $t,)*> {
				match *self {
					$($name::$t(ref mut a) => $name::$t(a),)*
				}
			}
		}
		impl_sum!(@into_inner $name : $($t)* : $first_a $($a)*);
		impl<$($t:AsRef<Target>,)* Target> AsRef<Target> for $name<$($t,)*> {
			fn as_ref(&self) -> &Target {
				match *self {
					$($name::$t(ref inner) => inner.as_ref(),)*
				}
			}
		}
		impl<$($t:AsMut<Target>,)* Target> AsMut<Target> for $name<$($t,)*> {
			fn as_mut(&mut self) -> &mut Target {
				match *self {
					$($name::$t(ref mut inner) => inner.as_mut(),)*
				}
			}
		}
		// TODO
		// impl<$($t:Deref,)*> Deref for $name<$($t,)*>
		// 	where $($t: Deref<Target=A::Target>,)*
		// {
		// 	type Target = A::Target;
		// 	fn deref(&self) -> &Self::Target {
		// 		match *self {
		// 			$($name::$t(ref inner) => &*inner,)*
		// 		}
		// 	}
		// }
		// impl<$($t:DerefMut,)*> DerefMut for $name<$($t,)*>
		// 	where $($t: DerefMut<Target=A::Target>,)*
		// {
		// 	fn deref_mut(&mut self) -> &mut Self::Target {
		// 		match *self {
		// 			$($name::$t(ref mut inner) => &mut *inner,)*
		// 		}
		// 	}
		// }
		impl<$($t:Error,)*> Error for $name<$($t,)*> {
			fn description(&self) -> &str {
				match *self {
					$($name::$t(ref inner) => inner.description(),)*
				}
			}
			fn cause(&self) -> Option<&Error> {
				match *self {
					$($name::$t(ref inner) => inner.cause(),)*
				}
			}
		}
		impl<$($t:Display,)*> Display for $name<$($t,)*> {
			fn fmt(&self, f: &mut Formatter) -> Result {
				match *self {
					$($name::$t(ref inner) => inner.fmt(f),)*
				}
			}
		}
	);
}

// TODO: impl_sum!(A Sum1 B Sum2 C Sum3 D Sum4 E Sum5 F Sum6);

impl_sum!(Sum0: : !);
impl_sum!(Sum1: A is_a map_a a: A);
impl_sum!(Sum2: A is_a map_a a B is_b map_b b: A A);
impl_sum!(Sum3: A is_a map_a a B is_b map_b b C is_c map_c c: A A A);
impl_sum!(Sum4: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d: A A A A);
impl_sum!(Sum5: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e: A A A A A);
impl_sum!(Sum6: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f: A A A A A A);
impl_sum!(Sum7: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g: A A A A A A A);
impl_sum!(Sum8: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h: A A A A A A A A);
impl_sum!(Sum9: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i: A A A A A A A A A);
impl_sum!(Sum10: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j: A A A A A A A A A A);
impl_sum!(Sum11: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k: A A A A A A A A A A A);
impl_sum!(Sum12: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l: A A A A A A A A A A A A);
impl_sum!(Sum13: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m: A A A A A A A A A A A A A);
impl_sum!(Sum14: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n: A A A A A A A A A A A A A A);
impl_sum!(Sum15: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o: A A A A A A A A A A A A A A A);
impl_sum!(Sum16: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p: A A A A A A A A A A A A A A A A);
impl_sum!(Sum17: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q: A A A A A A A A A A A A A A A A A);
impl_sum!(Sum18: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r: A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum19: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s: A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum20: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t: A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum21: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u: A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum22: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v: A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum23: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w: A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum24: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x: A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum25: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y: A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum26: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z: A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum27: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa: A A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum28: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa Ab is_ab map_ab ab: A A A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum29: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa Ab is_ab map_ab ab Ac is_ac map_ac ac: A A A A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum30: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa Ab is_ab map_ab ab Ac is_ac map_ac ac Ad is_ad map_ad ad: A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum31: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa Ab is_ab map_ab ab Ac is_ac map_ac ac Ad is_ad map_ad ad Ae is_ae map_ae ae: A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A);
impl_sum!(Sum32: A is_a map_a a B is_b map_b b C is_c map_c c D is_d map_d d E is_e map_e e F is_f map_f f G is_g map_g g H is_h map_h h I is_i map_i i J is_j map_j j K is_k map_k k L is_l map_l l M is_m map_m m N is_n map_n n O is_o map_o o P is_p map_p p Q is_q map_q q R is_r map_r r S is_s map_s s T is_t map_t t U is_u map_u u V is_v map_v v W is_w map_w w X is_x map_x x Y is_y map_y y Z is_z map_z z Aa is_aa map_aa aa Ab is_ab map_ab ab Ac is_ac map_ac ac Ad is_ad map_ad ad Ae is_ae map_ae ae Af is_af map_af af: A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A);

#[test]
fn basic() {
	let mut e = Sum2::A(2);
	let r = Sum2::B(2);
	assert_eq!(e, Sum2::A(2));
	e = r;
	assert_eq!(e, Sum2::B(2));
	assert_eq!(e.a(), None);
	assert_eq!(e.b(), Some(2));
	assert_eq!(e.as_ref().b(), Some(&2));
	assert_eq!(e.as_mut().b(), Some(&mut 2));
}