message: Add a doc explanation to each swizzle function.
diff: @@ -32,10 +32,12 @@ fn gen_swizzle_functions(variables: &'static str, upto: usize) -> String {
  let nn = (variables.len()+1).pow(upto as u32);
  for i in 1..nn {
  if let Some((swizzle_name, swizzle_impl)) = gen_swizzle_nth(variables, i, upto) {
  - let vec_type = format!("$vector_type{}", swizzle_name.len());
  + let dim = format!("{}", swizzle_name.len());
  result.push_str(
  - &format!(" #[inline] pub fn {0}(&self) -> {2}<$S> {{ {2}::new({1}) }}\n",
  - swizzle_name, swizzle_impl, vec_type));
  + &format!("
  + /// Swizzle operator that creates a new type with dimension {2} from variables `{0}`.
  + #[inline] pub fn {0}(&self) -> $vector_type{2}<$S> {{ $vector_type{2}::new({1}) }}\n",
  + swizzle_name, swizzle_impl, dim));
  }
  }
  result
  