# warn in log - Rust
Logs a message at the warn level.
Keywords: rust, rustlang, rust-lang, warn

# Macro log::warn

source · [−]

    macro_rules! warn {
        (target: $target:expr, $($arg:tt)+) => { ... };
        ($($arg:tt)+) => { ... };
    }

Expand description

Logs a message at the warn level.

## Examples

ⓘ

    use log::warn;

    let warn_description = "Invalid Input";

    warn!("Warning! {}!", warn_description);
    warn!(target: "input_events", "App received warning: {}", warn_description);