vector_var_imp_vec/
vector_var_imp_vec.rs

1use orx_imp_vec::*;
2use std::fmt::{Display, Formatter, Result};
3use std::ops::Index;
4
5struct Vector<'a> {
6    symbol: String,
7    created_vars: ImpVec<Var<'a>>,
8}
9
10impl<'a> Vector<'a> {
11    fn new(symbol: &str) -> Self {
12        Self {
13            symbol: symbol.into(),
14            created_vars: Default::default(),
15        }
16    }
17}
18
19impl<'a> Index<usize> for &'a Vector<'a> {
20    type Output = Var<'a>;
21
22    fn index(&self, index: usize) -> &Self::Output {
23        let var = Var {
24            index,
25            vector: self,
26        };
27        self.created_vars.imp_push_get_ref(var)
28    }
29}
30
31#[derive(Clone, Copy)]
32struct Var<'a> {
33    vector: &'a Vector<'a>,
34    index: usize,
35}
36
37impl<'a> Display for Var<'a> {
38    fn fmt(&self, f: &mut Formatter<'_>) -> Result {
39        write!(f, "{}[{}]", &self.vector.symbol, self.index)
40    }
41}
42
43fn main() {
44    let x = &Vector::new("x");
45
46    // good
47
48    let x0: Var = x[0];
49    assert_eq!(x0.to_string(), "x[0]");
50
51    // also good
52
53    let vars1: Vec<Var> = (0..1000).map(|i| x[i]).collect();
54
55    for (i, x) in vars1.iter().enumerate() {
56        assert_eq!(x.to_string(), format!("x[{}]", i));
57    }
58
59    // still good
60
61    let vars2: Vec<&Var> = (0..1000).map(|i| &x[i]).collect();
62
63    for (i, x) in vars2.iter().enumerate() {
64        assert_eq!(x.to_string(), format!("x[{}]", i));
65    }
66}
vector_var_imp_vec/vector_var_imp_vec.rs

vector_var_imp_vec/
vector_var_imp_vec.rs
