slog::log!

macro_rules! log {
    ($logger:ident, $lvl:expr, $msg:expr) => { ... };
    ($logger:ident, $lvl:expr, $msg : expr, $($k:expr => $v:expr),*) => { ... };
}

Log a custom level logging record

#[macro_use]
extern crate slog;

fn main() {
    let root = root_logger!("key" => "value");
    log!(root, slog::Level::Debug, "something happened", "counter" => 1);
}