Use structs with empty byte array fields for opaque types

Using empty enums could potentially cause undefined behavior

Author: crumblingstatue

src/audio/sound_buffer.rs

@@ -61,7 +61,10 @@ use std::slice;
 /// [`Sound`]: crate::audio::Sound
 #[derive(Debug)]
 #[allow(missing_copy_implementations)]
-pub enum SoundBuffer {}
+#[repr(C)]
+pub struct SoundBuffer {
+    _opaque: [u8; 0],
+}
 
 impl SoundBuffer {
     /// Save a sound buffer to an audio file

src/graphics/font.rs

@@ -51,7 +51,10 @@ use std::io::{Read, Seek};
 /// [`Text`]: crate::graphics::Text
 #[derive(Debug)]
 #[allow(missing_copy_implementations)]
-pub enum Font {}
+#[repr(C)]
+pub struct Font {
+    _opaque: [u8; 0],
+}
 
 impl Font {
     /// Get the kerning value corresponding to a given pair of characters in a font

src/graphics/texture.rs

@@ -49,7 +49,10 @@ use std::ptr;
 /// [`Color`]: crate::graphics::Color
 #[derive(Debug)]
 #[allow(missing_copy_implementations)]
-pub enum Texture {}
+#[repr(C)]
+pub struct Texture {
+    _opaque: [u8; 0],
+}
 
 impl Texture {
     /// Return the size of the texture

src/graphics/view.rs

@@ -10,7 +10,10 @@ use std::borrow::ToOwned;
 /// the way that your drawable objects are drawn.
 #[derive(Debug)]
 #[allow(missing_copy_implementations)]
-pub enum View {}
+#[repr(C)]
+pub struct View {
+    _opaque: [u8; 0],
+}
 
 impl View {
     /// Get the current orientation of a view