Function row_aligned 

pub fn row_aligned<'a, D, S>(
    align: Align,
    elements: Vec<Layout<'a, D, S>>,
) -> Layout<'a, D, S>

Creates a horizontal sequence of elements with the specified alignment applied to each immediate child.

Container nodes, by default, will only take up enough space to fit their contents.

If you want the container to take up as much space as is available you can use an expand modifier, or add an unconstrained node to it’s contents.

Unconstrained nodes can be conceptualized as “pushing” outwards & expanding their container, or pushing against other unconstrained nodes with equal force.