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#[cfg(feature = "logging")]
macro_rules! log {
    ( $fmt:expr ) => {
        println!($fmt);
    };
    ( $fmt:expr, $($x:tt)* ) => {
        println!($fmt, $($x)*);
    }
}

#[cfg(not(feature = "logging"))]
macro_rules! log {
    ( $fmt:expr ) => {};
    ( $fmt:expr, $($x:tt)* ) => {
        if false { let _ = format!($fmt, $($x)*); }
    };
}