rust-clippy/tests/ui/unnecessary_iter_cloned.rs

#![allow(unused_assignments)]
#![warn(clippy::unnecessary_to_owned)]

#[allow(dead_code)]
#[derive(Clone, Copy)]
enum FileType {
    Account,
    PrivateKey,
    Certificate,
}

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

    let _ = check_files(&[(FileType::Account, path)]);
    let _ = check_files_vec(vec![(FileType::Account, path)]);

    // negative tests
    let _ = check_files_ref(&[(FileType::Account, path)]);
    let _ = check_files_mut(&[(FileType::Account, path)]);
    let _ = check_files_ref_mut(&[(FileType::Account, path)]);
    let _ = check_files_self_and_arg(&[(FileType::Account, path)]);
    let _ = check_files_mut_path_buf(&[(FileType::Account, std::path::PathBuf::new())]);
}

// `check_files` and its variants are based on:
// https://github.com/breard-r/acmed/blob/1f0dcc32aadbc5e52de6d23b9703554c0f925113/acmed/src/storage.rs#L262
fn check_files(files: &[(FileType, &std::path::Path)]) -> bool {
    for (t, path) in files.iter().copied() {
        let other = match get_file_path(&t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

fn check_files_vec(files: Vec<(FileType, &std::path::Path)>) -> bool {
    for (t, path) in files.iter().copied() {
        let other = match get_file_path(&t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

fn check_files_ref(files: &[(FileType, &std::path::Path)]) -> bool {
    for (ref t, path) in files.iter().copied() {
        let other = match get_file_path(t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

#[allow(unused_assignments)]
fn check_files_mut(files: &[(FileType, &std::path::Path)]) -> bool {
    for (mut t, path) in files.iter().copied() {
        t = FileType::PrivateKey;
        let other = match get_file_path(&t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

fn check_files_ref_mut(files: &[(FileType, &std::path::Path)]) -> bool {
    for (ref mut t, path) in files.iter().copied() {
        *t = FileType::PrivateKey;
        let other = match get_file_path(t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

fn check_files_self_and_arg(files: &[(FileType, &std::path::Path)]) -> bool {
    for (t, path) in files.iter().copied() {
        let other = match get_file_path(&t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.join(path).is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

#[allow(unused_assignments)]
fn check_files_mut_path_buf(files: &[(FileType, std::path::PathBuf)]) -> bool {
    for (mut t, path) in files.iter().cloned() {
        t = FileType::PrivateKey;
        let other = match get_file_path(&t) {
            Ok(p) => p,
            Err(_) => {
                return false;
            },
        };
        if !path.is_file() || !other.is_file() {
            return false;
        }
    }
    true
}

fn get_file_path(_file_type: &FileType) -> Result<std::path::PathBuf, std::io::Error> {
    Ok(std::path::PathBuf::new())
}