rust 14 lines · 1 tab

Drop trait for custom cleanup logic

Marcus Chen Jan 2026

1 tab

struct Logger {
    name: String,
}

impl Drop for Logger {
    fn drop(&mut self) {
        println!("{} is being dropped", self.name);
    }
}

fn main() {
    let _logger = Logger { name: "MyLogger".to_string() };
    println!("End of main");
} // Logger dropped here

1 file · rust Explain with highlit

The Drop trait runs when a value goes out of scope, similar to destructors in C++. I implement Drop for resource handles: closing file descriptors, releasing locks, or logging cleanup. The drop method takes &mut self and can't fail (no Result). Rust calls Drop automatically; you rarely call it manually (use std::mem::drop() for explicit drops). Drop order is deterministic: values are dropped in reverse order of creation. For async cleanup, Drop can't call async functions, so I use a separate async fn shutdown() method. Drop is essential for RAII (Resource Acquisition Is Initialization), ensuring resources are freed even on panic.

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