Crate same_alloc

The SameVec makes it possible to re-use allocations across multiple invocations of zero-copy parsers.

This crate provides an allocated buffer that can be used by vectors of different element types, as long as they have the same layout. Most prominently this allows use of one buffer where the element type depends on a function local lifetime. The required vector type would be impossible to name outside the function.

Example

fn select_median_name(unparsed: &str) -> &str {
    // Problem: This type depends on the lifetime parameter. Ergo, we can not normally store
    // _one_vector in the surrounding function, and instead need to allocate here a new one.
    let mut names: Vec<_> = unparsed.split(' ').collect();
    let idx = names.len() / 2;
    *names.select_nth_unstable(idx).1
}

fn select_median_name_with_buffer<'names>(
    unparsed: &'names str,
    buf: &mut SameVec<*const str>,
) -> &'names str {
    let mut names = buf.use_for(same::for_ref());
    names.extend(unparsed.split(' '));
    let idx = names.len() / 2;
    *names.select_nth_unstable(idx).1
}

Re-exports

pub use crate::same::SameLayout;

Modules

same

Contains a proof type, demonstrating the layout equality of two types.

Structs

SameVec

A dynamically sized buffer for types with the same layout.

TempVec

A temporary view on a SameVec, with a different element type.