use this https://doc.rust-lang.org/std/path/struct.Path.html

[recmo]

On 2020-06-08 @pvienhage wrote in 18f47a6 “Autogen Bug Fixes to Rust Code (#706)”:

use this https://doc.rust-lang.org/std/path/struct.Path.html

    periodic: &RationalExpression,
    index: usize,
    name: &str,
    output_directory: &str,
) -> Result<(), std::io::Error> {
    // TODO - use this https://doc.rust-lang.org/std/path/struct.Path.html
    let name = format!("{}/{}.sol", output_directory, name);
    let path = Path::new(&name);
    let display = path.display();
    let mut file = match File::create(&path) {
        Err(why) => panic!("couldn't create {}: {}", display, why.to_string()),

From crypto/stark/src/solidity_verifier.rs:241