Place small arrays on the stack with a low cost!
The only price you should pay for this is the price of choosing
a type based on the size of the requested array! This is just one match and call!
This crate is created for one purpose: allocating small arrays on the stack. The simplest way to use it is:
use inplace_it::{inplace_or_alloc_array, UninitializedSliceMemoryGuard};
inplace_or_alloc_array(
150, // size of needed array to allocate
|mut uninit_guard: UninitializedSliceMemoryGuard<u16>| { // and this is consumer of uninitialized memory
// Size of stack-allocated memory can be more or equal to requested, but never less.
assert_eq!(160, uninit_guard.len());
{
// You can borrow guard to reuse memory
let borrowed_uninit_guard = uninit_guard.borrow();
// Let's initialize memory
// Note that borrowed_uninit_guard will be consumed (destroyed to produce initialized memory guard)
let init_guard = borrowed_uninit_guard.init(|index| index as u16 + 1);
// Memory now contains elements [1, 2, ..., 160]
// Lets check it. Sum of [1, 2, ..., 160] = 12880
let sum: u16 = init_guard.iter().sum();
assert_eq!(sum, 12880);
}
{
// If you don't want to reuse memory, you can init new guard directly
let init_guard = uninit_guard.init(|index| index as u16 * 2);
// Memory now contains elements [0, 2, 4, ..., 318]
// Lets check it. Sum of [0, 2, 4, ..., 318] = 25440
let sum: u16 = init_guard.iter().sum();
assert_eq!(sum, 25440);
}
}
)Because allocation on the stack (i.e. placing variables) is MUCH FASTER then usual allocating in the heap.
You can read the API reference for more details or create an new issue to submit a bug, feature request or just ask a question.
| Version | Notes |
|---|---|
| 0.3.5 | Remove useless FixedArray trait. |
| 0.3.4 | Fix incorrect use of unstable intrinsic. |
| 0.3.3 | Some sugar for easy placing from Iterator's. |
| 0.3.2 | Placing of uninit memory moved out from try_inplace_array to disallow compiler to optimize it. |
| 0.3.1 | Initialize with an exact-size iterator. |
| 0.3.0 |
|
| 0.2.2 | Fixed drop-correctness for safe functions. Now unsafe function do not drop your data but safe function do it correctly. |