Cleaned up new DependencyMap system

src/Discord.Net.Commands/Dependencies/DependencyMap.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Reflection;
 
 namespace Discord.Commands
 {
@@ -13,18 +12,6 @@ namespace Discord.Commands
             map = new Dictionary<Type, object>();
         }
 
-        public object Get(Type t)
-        {
-            if (!map.ContainsKey(t))
-                throw new KeyNotFoundException($"The dependency map does not contain \"{t.FullName}\"");
-            return map[t];
-        }
-
-        public T Get<T>() where T : class
-        {
-            return Get(typeof(T)) as T;
-        }
-
         public void Add<T>(T obj)
         {
             var t = typeof(T);
@@ -32,5 +19,37 @@ namespace Discord.Commands
                 throw new InvalidOperationException($"The dependency map already contains \"{t.FullName}\"");
             map.Add(t, obj);
         }
+
+        public T Get<T>()
+        {
+            return (T)Get(typeof(T));
+        }
+        public object Get(Type t)
+        {
+            object result;
+            if (!TryGet(t, out result))
+                throw new KeyNotFoundException($"The dependency map does not contain \"{t.FullName}\"");
+            else
+                return result;
+        }
+
+        public bool TryGet<T>(out T result)
+        {
+            object untypedResult;
+            if (TryGet(typeof(T), out untypedResult))
+            {
+                result = (T)untypedResult;
+                return true;
+            }
+            else
+            {
+                result = default(T);
+                return false;
+            }
+        }
+        public bool TryGet(Type t, out object result)
+        {
+            return map.TryGetValue(t, out result);
+        }
     }
 }

src/Discord.Net.Commands/Dependencies/IDependencyMap.cs

@@ -1,14 +1,15 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 
 namespace Discord.Commands
 {
     public interface IDependencyMap
     {
-        object Get(Type t);
-        T Get<T>() where T : class;
         void Add<T>(T obj);
+
+        T Get<T>();
+        bool TryGet<T>(out T result);
+
+        object Get(Type t);
+        bool TryGet(Type t, out object result);
     }
 }