com.google.common.collect.SingletonImmutableSet Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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/*
* 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 com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* Implementation of {@link ImmutableSet} with exactly one element.
*
* @author Kevin Bourrillion
* @author Nick Kralevich
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
@ElementTypesAreNonnullByDefault
final class SingletonImmutableSet extends ImmutableSet {
// We deliberately avoid caching the asList and hashCode here, to ensure that with
// compressed oops, a SingletonImmutableSet packs all the way down to the optimal 16 bytes.
final transient E element;
SingletonImmutableSet(E element) {
this.element = Preconditions.checkNotNull(element);
}
@Override
public int size() {
return 1;
}
@Override
public boolean contains(@CheckForNull Object target) {
return element.equals(target);
}
@Override
public UnmodifiableIterator iterator() {
return Iterators.singletonIterator(element);
}
@Override
public ImmutableList asList() {
return ImmutableList.of(element);
}
@Override
boolean isPartialView() {
return false;
}
@Override
int copyIntoArray(@Nullable Object[] dst, int offset) {
dst[offset] = element;
return offset + 1;
}
@Override
public final int hashCode() {
return element.hashCode();
}
@Override
public String toString() {
return '[' + element.toString() + ']';
}
// redeclare to help optimizers with b/310253115
@SuppressWarnings("RedundantOverride")
@Override
@J2ktIncompatible // serialization
@GwtIncompatible // serialization
Object writeReplace() {
return super.writeReplace();
}
}