A radioactive stabilization of the ptr_meta RFC.

Usage

Sized types

All Sized types have Pointee implemented for them with a blanket implementation. You do not need to derive Pointee for these types.

slices and strs

These core types have implementations built in.

dyn Any

The trait object for this standard library type comes with an implementation built in.

Structs with a DST as its last field

You can derive Pointee for structs with a trailing DST:

use ptr_meta::Pointee;

#[derive(Pointee)]
struct Block<H, T> {
    header: H,
    elements: [T],
}

Note that this will only work when the last field is guaranteed to be a DST. Structs with a generic last field may have a conflicting blanket impl since the generic type may be Sized. In these cases, a collection of specific implementations may be required with the generic parameter set to a slice, str, or specific trait object.

Trait objects

You can generate a Pointee implementation for trait objects:

use ptr_meta::pointee;

// Generates Pointee for dyn Stringy
#[pointee]
trait Stringy {
    fn as_string(&self) -> String;
}