Code shared from the Rust Playground

playground.rs

#[macro_use]
extern crate bitflags;

bitflags! {
    struct FileFlags: u32 {
        const DEVICE = 0b00000001;
        const EXECUTABLE = 0b00000010;
        const LOGFILE = 0b00000100;
        const BACKUP = 0b00001000;
        const DIRECTORY = 0b00010000;
        const CASCADE = 0b00100000;
        const IMMUTABLE = 0b01000000;
        const LOG_ACCESS = 0b10000000;
        
        const USER_FILE = Self::LOG_ACCESS.bits | Self::BACKUP.bits | Self::CASCADE.bits;
    }
}

struct File {
    flags: FileFlags,
    owner: usize,
}

fn main() {
    use std::collections::BTreeMap;

    let mut filesystem = BTreeMap::new();
    filesystem.insert("./my-app/err.log", File{flags: FileFlags::LOGFILE, owner: 1});
    filesystem.insert("./my-app/out.log", File{flags: FileFlags::LOGFILE, owner: 1});
    filesystem.insert("./my-app/app.conf", File{flags: FileFlags::BACKUP, owner: 1});
    filesystem.insert("./passwords.vault", File{flags: FileFlags::USER_FILE | FileFlags::IMMUTABLE, owner: 200});
    
    for (path, f) in &filesystem {
        if f.flags.contains(FileFlags::BACKUP) {
            println!("backing up {} for user {}", path, f.owner);
        }
    }
}