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

“callable entity - one for which the call operator may be applied — e.g., function, callable object, reference to either, and pointer to function; see also invocable entity.” (EMCppSfe 2021)