Cloneable file descriptor.

This allows a file descriptor to be cloned, ordered, compared, hashed etc.

Usage

#[derive(Clone)]
struct Event {
  file: CloneableFile,
}

fn process(vec: Vec<Event>) {}

let mut vec = Vec::new();
let file = CloneableFile::create("foo.txt")?;
vec.push(Event { file: file });
process(vec.clone());