Generalize buffer creation over the input type about gfx HOT 3 CLOSED

struct AttrPos {
    name: &'static str,
    count: uint,
    format: &'static str
}

impl AttrPos {
    fn new(n: &'static str, c: uint, f: &'static str) -> AttrPos {
        AttrPos { name: n, count: c, format: f }
    }
}

enum LayoutResult {
    Dynamic(Vec<AttrPos>),
    Static(&'static [AttrPos])
}

trait VertexLayout {
    fn layout(&self) -> LayoutResult;
}

/* and then a use: */
impl VertexLayout for Vertex {
        Static([
            AttrPos::new("color", 3, "f32"),
            AttrPos::new("normal", 3, "f32")
        ])
}