| /* |
| * Copyright (C) 2008 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 static com.google.common.base.Preconditions.checkState; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| |
| /** Precondition checks useful in collection implementations. */ |
| @GwtCompatible |
| final class CollectPreconditions { |
| |
| static void checkEntryNotNull(Object key, Object value) { |
| if (key == null) { |
| throw new NullPointerException("null key in entry: null=" + value); |
| } else if (value == null) { |
| throw new NullPointerException("null value in entry: " + key + "=null"); |
| } |
| } |
| |
| @CanIgnoreReturnValue |
| static int checkNonnegative(int value, String name) { |
| if (value < 0) { |
| throw new IllegalArgumentException(name + " cannot be negative but was: " + value); |
| } |
| return value; |
| } |
| |
| @CanIgnoreReturnValue |
| static long checkNonnegative(long value, String name) { |
| if (value < 0) { |
| throw new IllegalArgumentException(name + " cannot be negative but was: " + value); |
| } |
| return value; |
| } |
| |
| static void checkPositive(int value, String name) { |
| if (value <= 0) { |
| throw new IllegalArgumentException(name + " must be positive but was: " + value); |
| } |
| } |
| |
| /** |
| * Precondition tester for {@code Iterator.remove()} that throws an exception with a consistent |
| * error message. |
| */ |
| static void checkRemove(boolean canRemove) { |
| checkState(canRemove, "no calls to next() since the last call to remove()"); |
| } |
| } |