use std::mem;
use std::slice;

use alga::general::Real;
use na::{Point2, Point3, Vector2, Vector3};

/// Trait that transforms thing to a slice of u8.
pub trait AsBytes {
    fn as_bytes<'a>(&'a self) -> &'a [u8];
}

macro_rules! generic_as_bytes_impl(
    ($t: ident, $dimension: expr) => (
        impl<N: Real> AsBytes for $t<N> {
            #[inline(always)]
            fn as_bytes<'a>(&'a self) -> &'a [u8] {
                unsafe {
                    slice::from_raw_parts(mem::transmute(self), mem::size_of::<N>() * $dimension)
                }
            }
        }
    )
);

generic_as_bytes_impl!(Vector2, 2);
generic_as_bytes_impl!(Point2, 2);
generic_as_bytes_impl!(Vector3, 2);
generic_as_bytes_impl!(Point3, 2);

// FIXME: implement for all `T: Copy` insead?