https://RustRocket.rs -- Cloud Monk Losang Jinpa, Ph.D., MCSE / MCT, https://Rustaceans.rs, Full Stack Cloud Native Rust DevOps Engineer - Rocket Framework Rust Microservices on Kubernetes-AWS-Azure-GCP

“Collatz function - one that, given an integer N, returns N/2 if N is even, and 3N + 1 if N is odd; see also Collatz conjecture. constexpr Variables (313)” (EMCppSfe 2021)