message: Fix doc-test in context module.
diff: @@ -514,8 +514,8 @@ impl Context {
  /// # extern crate glium;
  /// # extern crate glutin;
  /// # fn main() {
  - /// # let display: glium::Display = unsafe { ::std::mem::uninitialized() };
  - /// let pixels: Vec<Vec<(u8, u8, u8, u8)>> = display.read_front_buffer();
  + /// # let display: glium::Display = unsafe { std::mem::MaybeUninit::uninit().assume_init() };
  + /// let pixels: Result<Vec<Vec<(u8, u8, u8, u8)>>, _> = display.read_front_buffer();
  /// # }
  /// ```
  pub fn read_front_buffer<T>(&self) -> Result<T, ops::ReadError>
  