Uninitialized buffers in Rust are a long-standing question, for example: https://rust-lang.github.io/rfcs/2930-read-buf.html https://doc.rust-lang.org/nightly/unstable-book/library-features/core-io-borrowed-buf.html https://blog.yoshuawuyts.com/uninit-read-write/ https://internals.rust-lang.org/t/reading-into-uninitialized-buffers-yet-again/13282/4 Recently, John Nunley and Alex Saveau came up wit