Future-proof some code for unsizedness (if we'll use extern types for…

… opaque types in the future)

src/cpp/fbox.rs

@@ -14,7 +14,7 @@ use std::{
 /// F stands for "foreign".
 pub struct FBox<T: ?Sized>(pub(crate) NonNull<T>);
 
-impl<T> std::fmt::Debug for FBox<T> {
+impl<T: ?Sized> std::fmt::Debug for FBox<T> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(
             f,
@@ -25,27 +25,27 @@ impl<T> std::fmt::Debug for FBox<T> {
     }
 }
 
-impl<T> FBox<T> {
+impl<T: ?Sized> FBox<T> {
     pub(crate) fn new(ptr: *mut T) -> Option<Self> {
         NonNull::new(ptr).map(FBox)
     }
 }
 
-impl<T> Deref for FBox<T> {
+impl<T: ?Sized> Deref for FBox<T> {
     type Target = T;
 
     fn deref(&self) -> &T {
         unsafe { self.0.as_ref() }
     }
 }
 
-impl<T> DerefMut for FBox<T> {
+impl<T: ?Sized> DerefMut for FBox<T> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         unsafe { self.0.as_mut() }
     }
 }
 
-impl<T> Borrow<T> for FBox<T> {
+impl<T: ?Sized> Borrow<T> for FBox<T> {
     fn borrow(&self) -> &T {
         self
     }

src/graphics/render_states.rs

@@ -33,7 +33,7 @@ use crate::graphics::{BlendMode, Shader, Texture, Transform};
 /// ```no_run
 /// # use sfml::graphics::*;
 /// # let mut window: RenderWindow = unimplemented!();
-/// # let shader: Shader = unimplemented!();
+/// # let shader: &Shader = unimplemented!();
 /// # let sprite: Sprite = unimplemented!();
 /// let mut states = RenderStates::default();
 /// states.shader = Some(&shader);

src/graphics/shader.rs

@@ -66,7 +66,7 @@ use {
 /// # use sfml::system::*;
 /// # use sfml::cpp::FBox;
 /// let texture: FBox<Texture> = unimplemented!();
-/// let mut shader: Shader = unimplemented!();
+/// let mut shader: &Shader = unimplemented!();
 /// let color: Color = unimplemented!();
 /// let transform: Transform = unimplemented!();
 /// shader.set_uniform_float("offset", 2.);
@@ -83,11 +83,11 @@ use {
 ///
 /// ```no_run
 /// # use sfml::graphics::*;
-/// # let shader: Shader = unimplemented!();
+/// # let shader: &Shader = unimplemented!();
 /// # let mut window: RenderWindow = unimplemented!();
 /// # let sprite: Sprite = unimplemented!();
 /// let mut states = RenderStates::default();;
-/// states.shader = Some(&shader);
+/// states.shader = Some(shader);
 /// window.draw_with_renderstates(&sprite, &states);
 /// ```
 ///
@@ -118,7 +118,7 @@ use {
 ///
 /// ```no_run
 /// use sfml::graphics::*;
-/// # let shader: Shader = unimplemented!();
+/// # let shader: &Shader = unimplemented!();
 /// Shader::bind(Some(&shader));
 /// // ... render OpenGL geometry ...
 /// Shader::bind(None);

src/lib.rs

@@ -79,7 +79,7 @@ impl IntoSfResult<()> for bool {
     }
 }
 
-impl<T> IntoSfResult<cpp::FBox<T>> for Option<cpp::FBox<T>> {
+impl<T: ?Sized> IntoSfResult<cpp::FBox<T>> for Option<cpp::FBox<T>> {
     fn into_sf_result(self) -> SfResult<cpp::FBox<T>> {
         self.ok_or(SfError::CallFailed)
     }