Macro layout 

macro_rules! layout {
    ($root:expr, $($e:expr $(=>  { $($t:tt)* })?),+$(,)?) => { ... };
}

Available on crate feature winio only.

Helper macro for layouts in Component::render.

let csize = self.window.client_size();
{
    let mut grid = layout! {
        Grid::from_str("1*,2*,1*", "1*,2*,1*").unwrap(),
        self.canvas => { column: 1, row: 1 },
    };
    grid.set_size(csize);
}