dyn-stack 0.1.1

Dynamic stack wrapper for unsized allocations
Documentation 
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

# dynstack
Stack that allows users to allocate dynamically sized arrays.
                                                                                               
The stack wraps a buffer of bytes that it uses as a workspace.
Allocating an array takes a chunk of memory from the stack, which can be reused once the array
is dropped.
                                                                                               
# Examples
```rust
use core::mem::MaybeUninit;
use dynstack::{DynStack, StackReq};
use reborrow::ReborrowMut;

// We allocate enough storage for 3 `i32` and 4 `u8`.
let mut buf = [MaybeUninit::uninit();
    StackReq::new::<i32>(3)
        .and(StackReq::new::<u8>(4))
        .unaligned_bytes_required()];
let mut stack = DynStack::new(&mut buf);

// We can have nested allocations.
// 3×`i32`
let (array_i32, substack) = stack.rb_mut().make_with::<i32, _>(3, |i| i as i32);
// and 4×`u8`
let (mut array_u8, _) = substack.make_with::<u8, _>(4, |_| 0);

// We can read from the arrays,
assert_eq!(array_i32[0], 0);
assert_eq!(array_i32[1], 1);
assert_eq!(array_i32[2], 2);

// and write to them.
array_u8[0] = 1;

assert_eq!(array_u8[0], 1);
assert_eq!(array_u8[1], 0);
assert_eq!(array_u8[2], 0);
assert_eq!(array_u8[3], 0);

// We can also have disjoint allocations.
// 3×`i32`
let (mut array_i32, _) = stack.rb_mut().make_with::<i32, _>(3, |i| i as i32);
assert_eq!(array_i32[0], 0);
assert_eq!(array_i32[1], 1);
assert_eq!(array_i32[2], 2);

// or 4×`u8`
let (mut array_u8, _) = stack.rb_mut().make_with::<i32, _>(4, |i| i as i32 + 3);
assert_eq!(array_u8[0], 3);
assert_eq!(array_u8[1], 4);
assert_eq!(array_u8[2], 5);
assert_eq!(array_u8[3], 6);
```