| /* |
| * Copyright (C) 2011 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 static com.google.common.base.Preconditions.checkArgument; |
| |
| import com.google.common.annotations.Beta; |
| import java.lang.reflect.Type; |
| import java.lang.reflect.TypeVariable; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * Captures a free type variable that can be used in {@link TypeToken#where}. For example: |
| * |
| * <pre>{@code |
| * static <T> TypeToken<List<T>> listOf(Class<T> elementType) { |
| * return new TypeToken<List<T>>() {} |
| * .where(new TypeParameter<T>() {}, elementType); |
| * } |
| * }</pre> |
| * |
| * @author Ben Yu |
| * @since 12.0 |
| */ |
| @Beta |
| public abstract class TypeParameter<T> extends TypeCapture<T> { |
| |
| final TypeVariable<?> typeVariable; |
| |
| protected TypeParameter() { |
| Type type = capture(); |
| checkArgument(type instanceof TypeVariable, "%s should be a type variable.", type); |
| this.typeVariable = (TypeVariable<?>) type; |
| } |
| |
| @Override |
| public final int hashCode() { |
| return typeVariable.hashCode(); |
| } |
| |
| @Override |
| public final boolean equals(@NullableDecl Object o) { |
| if (o instanceof TypeParameter) { |
| TypeParameter<?> that = (TypeParameter<?>) o; |
| return typeVariable.equals(that.typeVariable); |
| } |
| return false; |
| } |
| |
| @Override |
| public String toString() { |
| return typeVariable.toString(); |
| } |
| } |