https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn+main()+%7B%0A++++trait+A+%7B%7D%0A++++%0A++++let+_:+Box%3Cdyn+A+%2B+Send+%2B+Sync%3E;%0A%7D&edition=2024
Rust Playground
A browser interface to the Rust compiler to experiment with the language
rust playground