Struct PlayerIndex

pub struct PlayerIndex<const P: usize>(/* private fields */);

An index into a per-player collection that is guaranteed to be in-range for a game with P players.

Note that players are indexed from zero for consistency with the rest of Rust. That is, the first player in a game has index 0, the second player has index 1, and so on. This isn’t ideal since most of the literature on game theory uses one-based terminology. However, I judged internal consistency to be more important than external consistency, in this case. Juggling multiple different indexing styles within the code itself would be really confusing!

Implementations

impl<const P: usize> PlayerIndex<P>

pub fn new(index: usize) -> Option<Self>

Construct a new index into a PerPlayer collection. Returns None if the provided index value is out-of-range for the number of players in the game.

Predefined indexes for games of up to 16 players are defined in the forN modules.

Examples

use t4t::{for2, for8, PlayerIndex};

let p0_opt = PlayerIndex::<2>::new(0);
let p1_opt = PlayerIndex::<2>::new(1);
let p2_opt = PlayerIndex::<2>::new(2);

assert!(p0_opt.is_some());
assert!(p1_opt.is_some());
assert!(p2_opt.is_none());

assert_eq!(p0_opt.unwrap(), for2::P0);
assert_eq!(p1_opt.unwrap(), for2::P1);

assert_eq!(PlayerIndex::<8>::new(3).unwrap(), for8::P3);
assert_eq!(PlayerIndex::<8>::new(5).unwrap(), for8::P5);

pub fn as_usize(&self) -> usize

Get the player index as a plain usize value.

Examples

use t4t::{for3, for6};

assert_eq!(for3::P0.as_usize(), 0);
assert_eq!(for3::P2.as_usize(), 2);
assert_eq!(for6::P2.as_usize(), 2);
assert_eq!(for6::P5.as_usize(), 5);

pub fn num_players(&self) -> usize

Get the number of players in the game, which corresponds to the numbers of unique indexes in this type.

Examples

use t4t::{for5, for12};

assert_eq!(for5::P3.num_players(), 5);
assert_eq!(for12::P7.num_players(), 12);

pub fn all() -> PlayerIndexes<P>

Get an iterator that iterates over all player indexes of a given type.

Examples

use t4t::{for3, for5, PlayerIndex};

assert_eq!(
    PlayerIndex::all().collect::<Vec<PlayerIndex<3>>>(),
    vec![for3::P0, for3::P1, for3::P2]
);
assert_eq!(
    PlayerIndex::all().collect::<Vec<PlayerIndex<5>>>(),
    vec![for5::P0, for5::P1, for5::P2, for5::P3, for5::P4]
);

pub fn next(&self) -> Self

Get the index after this one, wrapping around to zero if this index is the last.

Examples

use t4t::{for2, for4, PlayerIndex};

assert_eq!(for2::P0.next(), for2::P1);
assert_eq!(for2::P1.next(), for2::P0);

assert_eq!(for4::P0.next(), for4::P1);
assert_eq!(for4::P1.next(), for4::P2);
assert_eq!(for4::P2.next(), for4::P3);
assert_eq!(for4::P3.next(), for4::P0);

pub fn previous(&self) -> Self

Get the index before this one, wrapping around to P-1 if this index is zero.

Examples

use t4t::{for2, for4, PlayerIndex};

assert_eq!(for2::P1.previous(), for2::P0);
assert_eq!(for2::P0.previous(), for2::P1);

assert_eq!(for4::P3.previous(), for4::P2);
assert_eq!(for4::P2.previous(), for4::P1);
assert_eq!(for4::P1.previous(), for4::P0);
assert_eq!(for4::P0.previous(), for4::P3);

Trait Implementations

impl<const P: usize> Clone for PlayerIndex<P>

fn clone(&self) -> PlayerIndex<P>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const P: usize> Debug for PlayerIndex<P>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const P: usize> Display for PlayerIndex<P>

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const P: usize> From<PlayerIndex<P>> for usize

fn from(index: PlayerIndex<P>) -> usize

Converts to this type from the input type.

impl<const P: usize> Hash for PlayerIndex<P>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T, const P: usize> Index<PlayerIndex<P>> for PerPlayer<T, P>

type Output = T

The returned type after indexing.

fn index(&self, idx: PlayerIndex<P>) -> &T

Performs the indexing (container[index]) operation.

impl<M, const P: usize> Index<PlayerIndex<P>> for Profile<M, P>

type Output = M

The returned type after indexing.

fn index(&self, idx: PlayerIndex<P>) -> &M

Performs the indexing (container[index]) operation.

impl<T, const P: usize> IndexMut<PlayerIndex<P>> for PerPlayer<T, P>

fn index_mut(&mut self, idx: PlayerIndex<P>) -> &mut T

Performs the mutable indexing (container[index]) operation.

impl<M, const P: usize> IndexMut<PlayerIndex<P>> for Profile<M, P>

fn index_mut(&mut self, idx: PlayerIndex<P>) -> &mut M

Performs the mutable indexing (container[index]) operation.

impl<const P: usize> PartialEq for PlayerIndex<P>

fn eq(&self, other: &PlayerIndex<P>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const P: usize> Copy for PlayerIndex<P>

impl<const P: usize> Eq for PlayerIndex<P>

impl<const P: usize> StructuralPartialEq for PlayerIndex<P>