Regression test for #17728

Closes #17728.

src/test/compile-fail/issue-17728.rs

@@ -0,0 +1,132 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::fmt::{Show, Formatter, Error};
+use std::collections::HashMap;
+
+trait HasInventory {
+    fn getInventory<'s>(&'s self) -> &'s mut Inventory;
+    fn addToInventory(&self, item: &Item);
+    fn removeFromInventory(&self, itemName: &str) -> bool;
+}
+
+trait TraversesWorld {
+    fn attemptTraverse(&self, room: &Room, directionStr: &str) -> Result<&Room, &str> {
+        let direction = str_to_direction(directionStr);
+        let maybe_room = room.direction_to_room.find(&direction);
+        //~^ ERROR cannot infer an appropriate lifetime for autoref due to conflicting requirements
+        match maybe_room {
+            Some(entry) => Ok(entry),
+            _ => Err("Direction does not exist in room.")
+        }
+    }
+}
+
+
+#[deriving(Show, Eq, PartialEq, Hash)]
+enum RoomDirection {
+    West,
+    East,
+    North,
+    South,
+    Up,
+    Down,
+    In,
+    Out,
+
+    None
+}
+
+struct Room {
+    description: String,
+    items: Vec<Item>,
+    direction_to_room: HashMap<RoomDirection, Room>,
+}
+
+impl Room {
+    fn new(description: &'static str) -> Room {
+        Room {
+            description: description.to_string(),
+            items: Vec::new(),
+            direction_to_room: HashMap::new()
+        }
+    }
+
+    fn add_direction(&mut self, direction: RoomDirection, room: Room) {
+        self.direction_to_room.insert(direction, room);
+    }
+}
+
+struct Item {
+    name: String,
+}
+
+struct Inventory {
+    items: Vec<Item>,
+}
+
+impl Inventory {
+    fn new() -> Inventory {
+        Inventory {
+            items: Vec::new()
+        }
+    }
+}
+
+struct Player {
+    name: String,
+    inventory: Inventory,
+}
+
+impl Player {
+    fn new(name: &'static str) -> Player {
+        Player {
+            name: name.to_string(),
+            inventory: Inventory::new()
+        }
+    }
+}
+
+impl TraversesWorld for Player {
+}
+
+impl Show for Player {
+    fn fmt(&self, formatter: &mut Formatter) -> Result<(), Error> {
+        formatter.write_str("Player{ name:");
+        formatter.write_str(self.name.as_slice());
+        formatter.write_str(" }");
+        Ok(())
+    }
+}
+
+fn str_to_direction(to_parse: &str) -> RoomDirection {
+    match to_parse {
+        "w" | "west" => RoomDirection::West,
+        "e" | "east" => RoomDirection::East,
+        "n" | "north" => RoomDirection::North,
+        "s" | "south" => RoomDirection::South,
+        "in" => RoomDirection::In,
+        "out" => RoomDirection::Out,
+        "up" => RoomDirection::Up,
+        "down" => RoomDirection::Down,
+        _ => None //~ ERROR mismatched types
+    }
+}
+
+fn main() {
+    let mut player = Player::new("Test player");
+    let mut room = Room::new("A test room");
+    println!("Made a player: {}", player);
+    println!("Direction parse: {}", str_to_direction("east"));
+    match player.attemptTraverse(&room, "west") {
+        Ok(_) => println!("Was able to move west"),
+        Err(msg) => println!("Not able to move west: {}", msg)
+    };
+}