1 files changed, 89 insertions, 0 deletions
diff --git a/guava/src/com/google/common/reflect/MutableTypeToInstanceMap.java b/guava/src/com/google/common/reflect/MutableTypeToInstanceMap.java
new file mode 100644
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--- /dev/null
+++ b/guava/src/com/google/common/reflect/MutableTypeToInstanceMap.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2012 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.common.reflect;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ForwardingMap;
+import com.google.common.collect.Maps;
+
+import java.util.Map;
+
+import javax.annotation.Nullable;
+
+/**
+ * A mutable type-to-instance map.
+ * See also {@link ImmutableTypeToInstanceMap}.
+ *
+ * @author Ben Yu
+ * @since 13.0
+ */
+@Beta
+public final class MutableTypeToInstanceMap<B> extends ForwardingMap<TypeToken<? extends B>, B>
+    implements TypeToInstanceMap<B> {
+
+  private final Map<TypeToken<? extends B>, B> backingMap = Maps.newHashMap();
+
+  @Nullable
+  @Override
+  public <T extends B> T getInstance(Class<T> type) {
+    return trustedGet(TypeToken.of(type));
+  }
+
+  @Nullable
+  @Override
+  public <T extends B> T putInstance(Class<T> type, @Nullable T value) {
+    return trustedPut(TypeToken.of(type), value);
+  }
+
+  @Nullable
+  @Override
+  public <T extends B> T getInstance(TypeToken<T> type) {
+    return trustedGet(type.rejectTypeVariables());
+  }
+
+  @Nullable
+  @Override
+  public <T extends B> T putInstance(TypeToken<T> type, @Nullable T value) {
+    return trustedPut(type.rejectTypeVariables(), value);
+  }
+
+  /** Not supported. Use {@link #putInstance} instead. */
+  @Override public B put(TypeToken<? extends B> key, B value) {
+    throw new UnsupportedOperationException("Please use putInstance() instead.");
+  }
+
+  /** Not supported. Use {@link #putInstance} instead. */
+  @Override public void putAll(Map<? extends TypeToken<? extends B>, ? extends B> map) {
+    throw new UnsupportedOperationException("Please use putInstance() instead.");
+  }
+
+  @Override protected Map<TypeToken<? extends B>, B> delegate() {
+    return backingMap;
+  }
+
+  @SuppressWarnings("unchecked") // value could not get in if not a T
+  @Nullable
+  private <T extends B> T trustedPut(TypeToken<T> type, @Nullable T value) {
+    return (T) backingMap.put(type, value);
+  }
+
+  @SuppressWarnings("unchecked") // value could not get in if not a T
+  @Nullable
+  private <T extends B> T trustedGet(TypeToken<T> type) {
+    return (T) backingMap.get(type);
+  }
+}