Struct PerPlayer

pub struct PerPlayer<T, const P: usize> { /* private fields */ }

A collection that stores one element corresponding to each player in a game.

The type is parameterized by the type of elements T and the number of players in the game P. For example, the type PerPlayer<f64, 3> contains exactly three f64 values, one for each player in a three-player game.

The “const generic” argument P is used to statically ensure that a PerPlayer collection contains the correct number of elements for a given game, and to provide statically checked indexing into PerPlayer collections.

Dynamically checked indexing operations

The get and get_mut methods allow indexing into a PerPlayer collection with plain usize indexes. They return references wrapped in an Option type, which may be None if the index is too large for the number of players in the game.

use t4t::PerPlayer;

let mut pp = PerPlayer::new(["klaatu", "barada", "nikto"]);
assert_eq!(pp.get(0), Some(&"klaatu"));
assert_eq!(pp.get(1), Some(&"barada"));
assert_eq!(pp.get(2), Some(&"nikto"));
assert_eq!(pp.get(3), None);

*pp.get_mut(0).unwrap() = "gort";
assert_eq!(pp.get(0), Some(&"gort"));

Statically checked indexing operations

The for_player and for_player_mut methods allow indexing into a PerPlayer collection with indexes of type PlayerIndex. An index of type PlayerIndex<P> is guaranteed to be in-range for a collection of type PerPlayer<T, P>, that is, indexing operations into a PerPlayer collection are guaranteed not to fail due to an index out-of-bounds error.

The Index and IndexMut traits are implemented using indexes of type PlayerIndex and are synonymous with the for_player and for_player_mut methods, respectively.

Indexes can be constructed dynamically using the PlayerIndex::new constructor. While the indexing operation cannot fail, constructing an index may fail if the index is out of bounds, in which case the constructor will return None.

use t4t::PlayerIndex;

assert!(PlayerIndex::<3>::new(0).is_some());
assert!(PlayerIndex::<3>::new(1).is_some());
assert!(PlayerIndex::<3>::new(2).is_some());
assert!(PlayerIndex::<3>::new(3).is_none());

When constructing indexes, often the value of P can be inferred from the type of the PerPlayer collection it is used to index into.

use t4t::{PerPlayer, PlayerIndex};

let mut pp = PerPlayer::new(["klaatu", "barada", "nikto"]);
let p0 = PlayerIndex::new(0).unwrap();
let p1 = PlayerIndex::new(1).unwrap();
let p2 = PlayerIndex::new(2).unwrap();
assert_eq!(pp[p0], "klaatu");
assert_eq!(pp[p1], "barada");
assert_eq!(pp[p2], "nikto");

pp[p0] = "gort";
assert_eq!(pp[p0], "gort");

Additionally, this module contains several submodules that predefine named indexes for all players up to a player count of 16. For example, the indexes for three player games are included in the for3 submodule.

use t4t::{for3, PerPlayer};

let mut pp = PerPlayer::new(["klaatu", "barada", "nikto"]);
assert_eq!(pp[for3::P0], "klaatu");
assert_eq!(pp[for3::P1], "barada");
assert_eq!(pp[for3::P2], "nikto");

pp[for3::P0] = "gort";
assert_eq!(pp[for3::P0], "gort");

Implementations

impl<T, const P: usize> PerPlayer<T, P>

pub fn new(data: [T; P]) -> Self

Create a new per-player collection from the given array.

pub fn generate<F: FnMut(PlayerIndex<P>) -> T>(gen_elem: F) -> Self

Create a new per-player collection by calling the given function with each player index, collecting the results.

Examples

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

let squared = |index: PlayerIndex<5>| {
    let val: usize = index.into();
    val * val
};
let squares = PerPlayer::generate(squared);
assert_eq!(squares[for5::P0], 0);
assert_eq!(squares[for5::P1], 1);
assert_eq!(squares[for5::P2], 4);
assert_eq!(squares[for5::P3], 9);
assert_eq!(squares[for5::P4], 16);

pub fn num_players(&self) -> usize

Get the number of players in the game, which corresponds to the number of elements in this collection.

pub fn get(&self, i: usize) -> Option<&T>

Get a reference to the element corresponding to the ith player in the game. Returns None if the index is out of range.

Examples

use t4t::PerPlayer;

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
assert_eq!(pp.get(0), Some(&"frodo"));
assert_eq!(pp.get(1), Some(&"sam"));
assert_eq!(pp.get(2), Some(&"merry"));
assert_eq!(pp.get(3), Some(&"pippin"));
assert_eq!(pp.get(4), None);

pub fn get_mut(&mut self, i: usize) -> Option<&mut T>

Get a mutable reference to the element corresponding to the ith player in the game. Returns None if the index is out of range.

Examples

use t4t::PerPlayer;

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
*pp.get_mut(1).unwrap() = "samwise";
*pp.get_mut(2).unwrap() = "meriadoc";
*pp.get_mut(3).unwrap() = "peregrin";
assert_eq!(pp.get(0), Some(&"frodo"));
assert_eq!(pp.get(1), Some(&"samwise"));
assert_eq!(pp.get(2), Some(&"meriadoc"));
assert_eq!(pp.get(3), Some(&"peregrin"));
assert_eq!(pp.get(4), None);

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

Index into a PerPlayer collection with a PlayerIndex. This operation is statically guaranteed not to fail.

Examples

use t4t::{for4, PerPlayer};

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
assert_eq!(*pp.for_player(for4::P0), "frodo");
assert_eq!(*pp.for_player(for4::P1), "sam");
assert_eq!(*pp.for_player(for4::P2), "merry");
assert_eq!(*pp.for_player(for4::P3), "pippin");

This method is used to implement the Index trait, which enables using the more concise indexing syntax.

use t4t::{for4, PerPlayer};

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
assert_eq!(pp[for4::P0], "frodo");
assert_eq!(pp[for4::P1], "sam");
assert_eq!(pp[for4::P2], "merry");
assert_eq!(pp[for4::P3], "pippin");

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

Index into a PerPlayer collection with PlayerIndex in a mutable context. This operation is statically guaranteed not to fail.

Examples

use t4t::{for4, PerPlayer};

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
*pp.for_player_mut(for4::P1) = "samwise";
*pp.for_player_mut(for4::P2) = "meriadoc";
*pp.for_player_mut(for4::P3) = "peregrin";
assert_eq!(*pp.for_player(for4::P0), "frodo");
assert_eq!(*pp.for_player(for4::P1), "samwise");
assert_eq!(*pp.for_player(for4::P2), "meriadoc");
assert_eq!(*pp.for_player(for4::P3), "peregrin");

This method is used to implement the IndexMut trait, which enables using the more concise indexing syntax.

use t4t::{for4, PerPlayer};

let mut pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);
pp[for4::P1] = "samwise";
pp[for4::P2] = "meriadoc";
pp[for4::P3] = "peregrin";
assert_eq!(pp[for4::P0], "frodo");
assert_eq!(pp[for4::P1], "samwise");
assert_eq!(pp[for4::P2], "meriadoc");
assert_eq!(pp[for4::P3], "peregrin");

impl<T: Clone, const P: usize> PerPlayer<T, P>

pub fn init_with(value: T) -> Self

Create a new per-player collection where each element is initialized with the given cloneable value.

pub fn for_each<F: FnMut(&T)>(&self, f: F)

Execute a function for each element in a per-player collection.

Examples

use t4t::PerPlayer;

let mut longest = "";
let pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);

pp.for_each(|s| {
   if s.len() > longest.len() {
     longest = s;
    }
});
assert_eq!(longest, "pippin");

pub fn for_each_with_index<F: FnMut(PlayerIndex<P>, &T)>(&self, f: F)

Execute a function for each element-index pair in a per-player collection.

Examples

use t4t::{for4, PerPlayer};

let mut longest = "";
let mut longest_index = for4::P0;
let pp = PerPlayer::new(["frodo", "sam", "pippin", "merry"]);

pp.for_each_with_index(|i, s| {
   println!("{}, {}, {}", i, s, s.len());
   if s.len() > longest.len() {
     println!("updating to {}, {}", i, s);
     longest = s;
     longest_index = i;
    }
});
assert_eq!(longest, "pippin");
assert_eq!(longest_index, for4::P2);

pub fn map<U, F: FnMut(T) -> U>(&self, f: F) -> PerPlayer<U, P>

Map a function over all elements in a per-player collection, producing a new per-player collection.

Examples

use t4t::PerPlayer;

let pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);

let mut lengths = pp.map(|s| s.len());
assert_eq!(lengths, PerPlayer::new([5, 3, 5, 6]));

let mut firsts = pp.map(|s| s.chars().next().unwrap());
assert_eq!(firsts, PerPlayer::new(['f', 's', 'm', 'p']));

pub fn map_with_index<U, F: FnMut(PlayerIndex<P>, T) -> U>( &self, f: F, ) -> PerPlayer<U, P>

Map a function over each element-index pair in a per-player collection, producing a new per-player collection.

Examples

use t4t::PerPlayer;

let pp = PerPlayer::new(["frodo", "sam", "merry", "pippin"]);

let mut pairs = pp.map_with_index(|i, s| (i.as_usize(), s.len()));
assert_eq!(pairs, PerPlayer::new([(0, 5), (1, 3), (2, 5), (3, 6)]));

let mut nths = pp.map_with_index(|i, s| s.chars().nth(i.as_usize()).unwrap());
assert_eq!(nths, PerPlayer::new(['f', 'a', 'r', 'p']));

impl<T: Debug, const P: usize> PerPlayer<Option<T>, P>

pub fn all_some(self) -> Option<PerPlayer<T, P>>

Converts a per-player collection of Option<T> values into a per-player collection of T values if every element in the initial collection is Some; otherwise returns None.

Examples

use t4t::PerPlayer;

assert_eq!(
    PerPlayer::new([Some(3), Some(4), Some(5)]).all_some(),
    Some(PerPlayer::new([3, 4, 5])),
);
assert_eq!(
    PerPlayer::new([Some(3), None, Some(5)]).all_some(),
    None,
);

impl<T, const P: usize> PerPlayer<T, P>

pub fn iter(&self) -> <&[T; P] as IntoIterator>::IntoIter

An iterator over references to elements in the per-player collection.

pub fn iter_mut(&mut self) -> <&mut [T; P] as IntoIterator>::IntoIter

An iterator over mutable references to elements in the per-player collection.

Trait Implementations

impl<T, const P: usize> AsMut<[T; P]> for PerPlayer<T, P>

fn as_mut(&mut self) -> &mut [T; P]

Converts this type into a mutable reference of the (usually inferred) input type.

impl<M, const P: usize> AsMut<PerPlayer<M, P>> for Profile<M, P>

fn as_mut(&mut self) -> &mut PerPlayer<M, P>

Converts this type into a mutable reference of the (usually inferred) input type.

impl<U, const P: usize> AsMut<PerPlayer<U, P>> for Payoff<U, P>

fn as_mut(&mut self) -> &mut PerPlayer<U, P>

Converts this type into a mutable reference of the (usually inferred) input type.

impl<T, const P: usize> AsRef<[T; P]> for PerPlayer<T, P>

fn as_ref(&self) -> &[T; P]

Converts this type into a shared reference of the (usually inferred) input type.

impl<M, const P: usize> AsRef<PerPlayer<M, P>> for Profile<M, P>

fn as_ref(&self) -> &PerPlayer<M, P>

Converts this type into a shared reference of the (usually inferred) input type.

impl<U, const P: usize> AsRef<PerPlayer<U, P>> for Payoff<U, P>

fn as_ref(&self) -> &PerPlayer<U, P>

Converts this type into a shared reference of the (usually inferred) input type.

impl<T: Clone, const P: usize> Clone for PerPlayer<T, P>

fn clone(&self) -> PerPlayer<T, P>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug, const P: usize> Debug for PerPlayer<T, P>

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

Formats the value using the given formatter.

impl<T: Default, const P: usize> Default for PerPlayer<T, P>

fn default() -> Self

Returns the “default value” for a type.

impl<T, const P: usize> From<[T; P]> for PerPlayer<T, P>

fn from(data: [T; P]) -> Self

Converts to this type from the input type.

impl<T: Hash, const P: usize> Hash for PerPlayer<T, 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<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<'a, T, const P: usize> IntoIterator for &'a PerPlayer<T, P>

type Item = <&'a [T; P] as IntoIterator>::Item

The type of the elements being iterated over.

type IntoIter = <&'a [T; P] as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> <&'a [T; P] as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<'a, T, const P: usize> IntoIterator for &'a mut PerPlayer<T, P>

type Item = <&'a mut [T; P] as IntoIterator>::Item

The type of the elements being iterated over.

type IntoIter = <&'a mut [T; P] as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> <&'a mut [T; P] as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<T, const P: usize> IntoIterator for PerPlayer<T, P>

type Item = <[T; P] as IntoIterator>::Item

The type of the elements being iterated over.

type IntoIter = <[T; P] as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> <[T; P] as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<T: Ord, const P: usize> Ord for PerPlayer<T, P>

fn cmp(&self, other: &PerPlayer<T, P>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: PartialEq, const P: usize> PartialEq for PerPlayer<T, P>

fn eq(&self, other: &PerPlayer<T, 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<T: PartialOrd, const P: usize> PartialOrd for PerPlayer<T, P>

fn partial_cmp(&self, other: &PerPlayer<T, P>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Copy, const P: usize> Copy for PerPlayer<T, P>

impl<T: Eq, const P: usize> Eq for PerPlayer<T, P>

impl<T, const P: usize> StructuralPartialEq for PerPlayer<T, P>