Hi. I'm trying to compile this code, but it unexpectedly fails (I tried to reduce it to the smallest example possible).

#![feature(ptr_metadata)]

use std::ptr::{Pointee, DynMetadata};

trait Bar {}

impl<T> Bar for [T] {}

// error[E0119]: conflicting implementations of trait `Bar` for type `[_]`
impl<T> Bar for T
where
    T: Pointee<Metadata = DynMetadata<T>> + ?Sized,
{}

try on playground: Rust Playground

Rust version: 1.95.0-nightly (2026-02-02), playground.

So, is something I'm doing wrong or is it too complex for the compiler to understand that [T] never implements Pointee<Metadata = DynMetadata<T>>?

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