1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162

use fxhash::FxHashMap;
use std::any::{Any, TypeId};

/// TypeID based map for storing different types
#[derive(Default)]
pub struct TypeMap {
    map: FxHashMap<TypeId, Box<dyn Any>>,
}

impl TypeMap {
    /// Create new empty map (wrapper to default)
    #[inline]
    pub fn new() -> Self {
        Self::default()
    }

    /// Insert a value to map
    pub fn insert<T: 'static>(&mut self, val: T) {
        self.map.insert(TypeId::of::<T>(), Box::new(val));
    }

    /// Get immutable reference to entry
    pub fn get<T: 'static>(&self) -> Option<&T> {
        self.map
            .get(&TypeId::of::<T>())
            .and_then(|boxed| boxed.downcast_ref())
    }

    /// Get mutable reference to entry
    pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T> {
        self.map
            .get_mut(&TypeId::of::<T>())
            .and_then(|boxed| boxed.downcast_mut())
    }

    /// Check if map contains specific type
    #[inline]
    pub fn contains<T: 'static>(&self) -> bool {
        self.map.contains_key(&TypeId::of::<T>())
    }

    /// Remove entry from map
    pub fn remove<T: 'static>(&mut self) -> Option<T> {
        self.map
            .remove(&TypeId::of::<T>())
            .and_then(|boxed| boxed.downcast().ok().map(|boxed| *boxed))
    }

    /// Clear whole map
    #[inline]
    pub fn clear(&mut self) {
        self.map.clear()
    }
}

#[test]
fn test_mut() {
    let mut map = TypeMap::new();

    map.insert(String::from("Hello, "));

    map.get_mut::<String>()
        .map(|v| v.push_str("world!"))
        .unwrap();

    assert_eq!("Hello, world!", map.get::<String>().unwrap());
}

#[test]
fn test_remove() {
    let mut map = TypeMap::new();

    map.insert::<i8>(123);
    assert!(map.get::<i8>().is_some());

    map.remove::<i8>();
    assert!(!map.get::<i8>().is_some());
}

#[test]
fn test_clear() {
    let mut map = TypeMap::new();

    map.insert::<i8>(8);
    map.insert::<i16>(16);
    map.insert::<i32>(32);

    assert!(map.contains::<i8>());
    assert!(map.contains::<i16>());
    assert!(map.contains::<i32>());

    map.clear();

    assert!(!map.contains::<i8>());
    assert!(!map.contains::<i16>());
    assert!(!map.contains::<i32>());

    map.insert::<i8>(10);
    assert_eq!(*map.get::<i8>().unwrap(), 10);
}

#[test]
fn test_integers() {
    let mut map = TypeMap::new();

    map.insert::<i8>(8);
    assert!(map.get::<i8>().is_some());

    map.insert::<i16>(16);
    assert!(map.get::<i16>().is_some());

    map.insert::<i32>(32);
    assert!(map.get::<i32>().is_some());

    map.insert::<i64>(64);
    assert!(map.get::<i64>().is_some());

    map.insert::<i128>(128);
    assert!(map.get::<i128>().is_some());

    map.insert::<u8>(8);
    assert!(map.get::<i8>().is_some());

    map.insert::<u16>(16);
    assert!(map.get::<i16>().is_some());

    map.insert::<u32>(32);
    assert!(map.get::<i32>().is_some());

    map.insert::<u64>(64);
    assert!(map.get::<i64>().is_some());

    map.insert::<u128>(128);
    assert!(map.get::<i128>().is_some());
}

#[test]
fn test_composition() {
    struct Magi<T>(pub T);

    struct Madoka {
        pub is_rei: bool,
    }

    struct Homura {
        pub attempts: usize,
    }

    struct Mami {
        pub guns: usize,
    }

    let mut map = TypeMap::new();

    map.insert(Magi(Madoka { is_rei: false }));
    map.insert(Magi(Homura { attempts: 0 }));
    map.insert(Magi(Mami { guns: 999 }));

    assert_eq!(false, map.get::<Magi<Madoka>>().unwrap().0.is_rei);
    assert_eq!(0, map.get::<Magi<Homura>>().unwrap().0.attempts);
    assert_eq!(999, map.get::<Magi<Mami>>().unwrap().0.guns);
}