Path has no Default

[Nicholas-Baron]

Ran into this doing a pull request.

The Path struct has no impl Default documented, but a value of Path::new("") seems to be a good default in my mind. (Update: it is not, I have been corrected)

This may be the incorrect way to ask for such a thing, but I would like to know why there is no impl Default for Path and whether there could be one in the near future.

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[jonas-schievink]

What does an empty path mean? Does it refer to the current directory?

[Nicholas-Baron]

@jonas-schievink Currently, the empty path refers to (at least on Linux) a nonexistent file or directory.
Code to test this

use std::path::Path;

fn main() {
    let path = Path::new("");

    println!("Empty string path");
    println!("{}", path.display());
    println!("Exists: {}", path.exists());
    match path.canonicalize() {
        Ok(p) => println!("{}", p.display()),
        Err(e) => println!("error {}", e),
    }
}

[jonas-schievink]

Hmm, I'm not sure why it would be a good default then

[Nicholas-Baron]

So the question shifts from "is "" a good default" to "is there any good default for Path". (Second part of initial issue)
Even if there are multiple candidates, we can simply select the best of them and make that be the impl Default for Path.

[CryZe]

If there's no clear default, then it probably should not have a Default impl at all, though maybe "." could work and be clear enough? Not sure.

[Nicholas-Baron]

This issue seems to have been just me exploring why there is no impl Default for Path.
In summary,

1. "" is an invalid path.
2. The current directory can be accessed differently (see std::env::current_dir()).
3. The root directory is unsuitable (Windows does not have a concept of "root", usually protected on Unix).
4. Any other directory would be arbitrary and should use Path::new

I thank everyone for their contributions and apologize for wasting time.