The directory layout of a Rust project should look like this (source)
.
├── Cargo.lock
├── Cargo.toml
├── benches
│ └── large-input.rs
├── examples
│ └── simple.rs
├── src
│ ├── bin
│ │ └── another_executable.rs
│ ├── lib.rs
│ └── main.rs
└── tests
└── some-integration-tests.rs
What is the file simple.rs under examples? How do I execute it? How should the file look like?