Use failure crate for error handling in examples/animation.rs

Cargo.toml

@@ -33,6 +33,7 @@ version = ">= 1.0, <= 1.3"
 optional = true
 
 [dev-dependencies]
+failure = "0.1.6"
 rand = "^0.7"
 
 [features]

examples/animation.rs

@@ -1,21 +1,24 @@
+extern crate failure;
 extern crate sdl2;
+
 use std::path::Path;
 
+use failure::Error;
 use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
 use sdl2::rect::Rect;
 use sdl2::rect::Point;
 use std::time::Duration;
 
-fn main() -> Result<(), String> {
+fn main() -> Result<(), Error> {
     let sdl_context = sdl2::init()?;
     let video_subsystem = sdl_context.video()?;
 
     let window = video_subsystem.window("SDL2", 640, 480)
-        .position_centered().build().map_err(|e| e.to_string())?;
+        .position_centered().build()?;
 
     let mut canvas = window.into_canvas()
-        .accelerated().build().map_err(|e| e.to_string())?;
+        .accelerated().build()?;
     let texture_creator = canvas.texture_creator();
 
     canvas.set_draw_color(sdl2::pixels::Color::RGBA(0,0,0,255));
@@ -27,8 +30,7 @@ fn main() -> Result<(), String> {
     // animation sheet and extras are available from
     // https://opengameart.org/content/a-platformer-in-the-forest
     let temp_surface = sdl2::surface::Surface::load_bmp(Path::new("assets/characters.bmp"))?;
-    let texture = texture_creator.create_texture_from_surface(&temp_surface)
-        .map_err(|e| e.to_string())?;
+    let texture = texture_creator.create_texture_from_surface(&temp_surface)?;
 
     let frames_per_anim = 4;
     let sprite_tile_size = (32,32);