🔗 Crate Squatting

Reserving one or more crate names on crates.io for future use by publishing a placeholder crate. While this practice is not forbidden, it is also frowned upon by some, and can be reverted in extreme or malicious cases.

🔗 Dtolnay Trick

See semver trick.

🔗 Eat your Laundry

Metaphorical expression for a consequence of undefined behavior. It is often used in the Rust community as an alternative to nasal demons.


🔗 Fearless concurrency

The expression stems from the capability of writing risk-free Rust code without data races or other memory safety bugs. Despite the loaded meaning, mentioning that "Rust has fearless concurrency" alone does not make a very good argument in a conversation on whether to use Rust or not.


🔗 Ferris

Ferris the crab is the unofficial Rust mascot. Official website: rustacean.net

🔗 Generic Associated Types

Acronym: GATs

An extension to Rust (RFC1598) which allows for lifetime parameters and type parameters in associated types of a trait. Often referred to by their acronym, GATs were one of the features highly anticipated by some members of the community.

Five years after the RFC was approved, a baseline implementation was finally made stable in version 1.65.0.

🔗 Hearty Boy

Higher-ranked trait bounds (HRTB).

It is a mnemonic for the HRTB acronym.

🔗 Owl Result

Result<(), ()> - a result type with () for both T and E parameter types.

The brackets, empty tuples and comma resemble an owl's head.

🔗 Pre-Poop Your Pants

Acronym: PPYP

In unsafe code, preemptively guarantee that a panic or incorrect API usage in safe code will result in logical errors rather than undefined behaviour. See Pre-Pooping Your Pants With Rust.

🔗 Rewrite in Rust

Also known as rewrite it in Rust (RIIR).

A proposition or idea of porting existing software to Rust. See also Rust Evangelism Strike Force

🔗 Rust Evangelism Strike Force

Acronym: RESF

A movement of proponents of Rust, who usually talk to their peers about the benefits of the language, and may also be in favor of rewriting existing software in Rust. As in all movements, different levels of adherence to the principles of the RESF exist, not all of which represent a healthy conduct. A zealous attitude may often be used for humor (see /r/rustjerk), but is not well regarded when taken seriously.

🔗 Rustacean

A Rust developer. A word play between Rust and crustacean, alluding to the mascot Ferris.

A community maintained list of Rustaceans is available at www.rustaceans.org.

🔗 Semver Trick

Also known as the dtolnay trick, a trick for Rust libraries to publish breaking changes without requiring other crates around the ecosystem to upgrade in a coordinated fashion.

Official reference: github.com/dtolnay/semver-trick

🔗 Toilet Closure

|_| () A closure that takes one parameter and immediately drops it. Equivalent in behavior to std::mem::drop, although not always interchangeable. Named as such because it looks like a toilet with the flush tank and bowl next to each other. It may seem to be rotated 90 degrees counter-clockwise or observed from the side, depending on personal perspective and interpretation.

Despite drop being easier to type than the toilet closure, there is currently no community-wide consensus on whether one should write the former or the latter.

🔗 Turbofish


Turbofish, or turbo fish, is the base syntax for defining type parameters explicitly when using a generic type or function.

Although this syntax may seem verbose and largely unnecessary given the prior art of type parameters, the turbofish actually cannot be removed from the Rust language. The proof of the turbofish's invincibility has been written into a memorial: the Bastion of the Turbofish.

See also turbo.fish.