Easily add a --port
flag to CLIs using Structopt.
```rust extern crate clapportflag;
use structopt::StructOpt; use clapportflag::Port;
struct Cli { #[structopt(flatten)] port: Port, }
fn main() { let args = Cli::fromargs(); let _tcplistener = args.port.bind().unwrap(); } ```
sh
$ cargo add clap-port-flag
MIT OR Apache-2.0