allow inlining (this did not provide a statistically significant performance boost - oh well)

src/mock.rs

@@ -4,6 +4,7 @@ use crate::game::{RoomType, RoomFormat};
 pub mod image {
     use crate::Image;
 
+    #[inline]
     pub(crate) fn chequers_1() -> Image {
         Image {
             pixels: vec![
@@ -14,6 +15,7 @@ pub mod image {
         }
     }
 
+    #[inline]
     pub fn chequers_2() -> Image {
         Image {
             pixels: vec![
@@ -25,6 +27,7 @@ pub mod image {
     }
 }
 
+#[inline]
 pub fn avatar() -> Sprite {
     Sprite {
         id: 0,
@@ -53,6 +56,7 @@ pub fn avatar() -> Sprite {
     }
 }
 
+#[inline]
 pub fn tile_default() -> Tile {
     Tile {
         id: 10,
@@ -69,6 +73,7 @@ pub fn tile_default() -> Tile {
     }
 }
 
+#[inline]
 pub fn sprite() -> Sprite {
     Sprite {
         id: 10,
@@ -88,6 +93,7 @@ pub fn sprite() -> Sprite {
     }
 }
 
+#[inline]
 pub fn item() -> Item {
     Item {
         id: 6,
@@ -104,6 +110,7 @@ pub fn item() -> Item {
     }
 }
 
+#[inline]
 pub fn room() -> Room {
     Room {
         id: 10,
@@ -407,6 +414,7 @@ pub fn room() -> Room {
     }
 }
 
+#[inline]
 pub fn game_default() -> Game {
     Game {
         name: "Write your game's title here".to_string(),