Stack-allocated dynamically-sized types

Overview

This crate provides a simple way of returnings DSTs up to a certain size without requiring a heap allocation.

Basic usage

The core type is StackDST<Trait>, which represents a fixed-capacity allocation of an unsized type. The new method on this type allows creating a instance from a concrete type, returning Err(value) if the instance is too large for the allocated region.

Example

One of the most obvious uses is to allow returning capturing closures without having to box them. In the example below, the closure takes ownership of value, and is saved to a StackDST

use stack_dst::StackDST;

fn make_closure(value: u64) -> StackDST<Fn()->String> {
    StackDST::new(move || format!("Hello there! value={}", value)).ok().expect("Closure doesn't fit")
}
let closure = make_closure(12);
assert_eq!( closure(), "Hello there! value=12" );

Status

• Works for most test cases
• Not rigourously tested
• No support for heap fallback