dbsp/dynamic/
pair.rs

1use std::mem::take;
2
3use crate::{DBData, declare_trait_object, dynamic::erase::Erase, utils::Tup2};
4
5use super::{Data, DataTrait};
6
7/// A dynamically typed interface to `Tup2`.
8pub trait Pair<T1: DataTrait + ?Sized, T2: DataTrait + ?Sized>: Data {
9    /// Return a reference to the first component of the tuple.
10    fn fst(&self) -> &T1;
11
12    /// Return a reference to the second component of the tuple.
13    fn snd(&self) -> &T2;
14
15    /// Return a mutable reference to the first component of the tuple.
16    fn fst_mut(&mut self) -> &mut T1;
17
18    /// Return a mutable reference to the second component of the tuple.
19    fn snd_mut(&mut self) -> &mut T2;
20
21    /// Return a pair of references to the values stored in the tuple.
22    fn split(&self) -> (&T1, &T2);
23
24    /// Return a pair of mutable references to the values stored in the tuple.
25    fn split_mut(&mut self) -> (&mut T1, &mut T2);
26
27    /// Clone the values of `fst` anf `snd` to the first and second components of the tuple.
28    #[allow(clippy::wrong_self_convention)]
29    fn from_refs(&mut self, fst: &T1, snd: &T2);
30
31    /// Move `fst` and `snd` into the first and second components of the tuple without cloning.
32    /// Sets the contents of `fst` and `snd` to default values.
33    #[allow(clippy::wrong_self_convention)]
34    fn from_vals(&mut self, fst: &mut T1, snd: &mut T2);
35}
36
37impl<T1, T2, Trait1, Trait2> Pair<Trait1, Trait2> for Tup2<T1, T2>
38where
39    T1: DBData + Erase<Trait1>,
40    T2: DBData + Erase<Trait2>,
41    Trait1: DataTrait + ?Sized,
42    Trait2: DataTrait + ?Sized,
43{
44    fn fst(&self) -> &Trait1 {
45        self.0.erase()
46    }
47
48    fn fst_mut(&mut self) -> &mut Trait1 {
49        self.0.erase_mut()
50    }
51
52    fn snd(&self) -> &Trait2 {
53        self.1.erase()
54    }
55
56    fn snd_mut(&mut self) -> &mut Trait2 {
57        self.1.erase_mut()
58    }
59
60    fn split(&self) -> (&Trait1, &Trait2) {
61        (self.0.erase(), self.1.erase())
62    }
63
64    fn split_mut(&mut self) -> (&mut Trait1, &mut Trait2) {
65        (self.0.erase_mut(), self.1.erase_mut())
66    }
67
68    fn from_refs(&mut self, fst: &Trait1, snd: &Trait2) {
69        unsafe {
70            self.0 = fst.downcast::<T1>().clone();
71            self.1 = snd.downcast::<T2>().clone();
72        }
73    }
74
75    fn from_vals(&mut self, fst: &mut Trait1, snd: &mut Trait2) {
76        unsafe {
77            self.0 = take(fst.downcast_mut::<T1>());
78            self.1 = take(snd.downcast_mut::<T2>());
79        }
80    }
81}
82
83declare_trait_object!(DynPair<T1, T2> = dyn Pair<T1, T2>
84where
85    T1: DataTrait + ?Sized,
86    T2: DataTrait + ?Sized,
87);
dbsp/dynamic/pair.rs

dbsp/dynamic/
pair.rs
