Function stl_io::write_stl

pub fn write_stl<'a, W, I>(writer: &mut W, mesh: I) -> Result<()> where
    W: Write,
    I: ExactSizeIterator<Item = &'a Triangle>, 

Write to std::io::Write as documented in Wikipedia.

let mesh = [stl_io::Triangle { normal: [1.0, 0.0, 0.0],
                               vertices: [[0.0, -1.0, 0.0],
                                          [0.0, 1.0, 0.0],
                                          [0.0, 0.0, 0.5]]}];
let mut binary_stl = Vec::<u8>::new();
stl_io::write_stl(&mut binary_stl, mesh.iter()).unwrap();