/*
* Copyright (C) 2007 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.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.Map;
import javax.annotation.Nullable;
/**
* A map, each entry of which maps a Java
* <a href="http://tinyurl.com/2cmwkz">raw type</a> to an instance of that type.
* In addition to implementing {@code Map}, the additional type-safe operations
* {@link #putInstance} and {@link #getInstance} are available.
*
* <p>Like any other {@code Map<Class, Object>}, this map may contain entries
* for primitive types, and a primitive type and its corresponding wrapper type
* may map to different values.
*
* @param <B> the common supertype that all entries must share; often this is
* simply {@link Object}
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface ClassToInstanceMap<B> extends Map<Class<? extends B>, B> {
/**
* Returns the value the specified class is mapped to, or {@code null} if no
* entry for this class is present. This will only return a value that was
* bound to this specific class, not a value that may have been bound to a
* subtype.
*/
<T extends B> T getInstance(Class<T> type);
/**
* Maps the specified class to the specified value. Does <i>not</i> associate
* this value with any of the class's supertypes.
*
* @return the value previously associated with this class (possibly {@code
* null}), or {@code null} if there was no previous entry.
*/
<T extends B> T putInstance(Class<T> type, @Nullable T value);
}
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