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Diffstat (limited to 'guava/src/com/google/common/reflect/TypeParameter.java')
-rw-r--r-- | guava/src/com/google/common/reflect/TypeParameter.java | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/guava/src/com/google/common/reflect/TypeParameter.java b/guava/src/com/google/common/reflect/TypeParameter.java new file mode 100644 index 0000000..79bf076 --- /dev/null +++ b/guava/src/com/google/common/reflect/TypeParameter.java @@ -0,0 +1,67 @@ +/* + * 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 javax.annotation.Nullable; + +/** + * 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(@Nullable Object o) { + if (o instanceof TypeParameter) { + TypeParameter<?> that = (TypeParameter<?>) o; + return typeVariable.equals(that.typeVariable); + } + return false; + } + + @Override public String toString() { + return typeVariable.toString(); + } +} |