diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/DoubleToOptionalFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/DoubleToOptionalFunction.java
deleted file mode 100644
index ebc9326..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/DoubleToOptionalFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.Optional;
-import java.util.function.DoubleFunction;
-
-/**
- * DoubleToOptionalFunction
- *
- *
- * 接受类型为 double 的参数,返回 {@code Optional<R>} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see Optional
- * @see DoubleFunction
- */
-@FunctionalInterface
-public interface DoubleToOptionalFunction extends DoubleFunction> {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/IntToOptionalFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/IntToOptionalFunction.java
deleted file mode 100644
index 9ba3048..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/IntToOptionalFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.Optional;
-import java.util.function.IntFunction;
-
-/**
- * IntToOptionalFunction
- *
- *
- * 接受类型为 int 的参数,返回 {@code Optional<R>} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see Optional
- * @see IntFunction
- */
-@FunctionalInterface
-public interface IntToOptionalFunction extends IntFunction> {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/LongToOptionalFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/LongToOptionalFunction.java
deleted file mode 100644
index f765fae..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/LongToOptionalFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.Optional;
-import java.util.function.LongFunction;
-
-/**
- * LongToOptionalFunction
- *
- *
- * 接受类型为 long 的参数,返回 {@code Optional<R>} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see Optional
- * @see LongFunction
- */
-@FunctionalInterface
-public interface LongToOptionalFunction extends LongFunction> {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalDoubleSupplier.java b/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalDoubleSupplier.java
deleted file mode 100644
index 8d6ba65..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalDoubleSupplier.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalDouble;
-import java.util.function.Supplier;
-
-/**
- * OptionalDoubleSupplier
- *
- *
- * 返回 {@link OptionalDouble} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalDouble
- * @see Supplier
- */
-@FunctionalInterface
-public interface OptionalDoubleSupplier extends Supplier {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalIntSupplier.java b/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalIntSupplier.java
deleted file mode 100644
index 70621ba..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalIntSupplier.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalInt;
-import java.util.function.Supplier;
-
-/**
- * OptionalIntSupplier
- *
- *
- * 返回 {@link OptionalInt} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalInt
- * @see Supplier
- */
-@FunctionalInterface
-public interface OptionalIntSupplier extends Supplier {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalLongSupplier.java b/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalLongSupplier.java
deleted file mode 100644
index 6636cad..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/OptionalLongSupplier.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalLong;
-import java.util.function.Supplier;
-
-/**
- * OptionalLongSupplier
- *
- *
- * 返回 {@link OptionalLong} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalLong
- * @see Supplier
- */
-@FunctionalInterface
-public interface OptionalLongSupplier extends Supplier {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalDoubleFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalDoubleFunction.java
deleted file mode 100644
index e50fc8e..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalDoubleFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalDouble;
-import java.util.function.Function;
-
-/**
- * ToOptionalDoubleFunction
- *
- *
- * 接受类型为 T 的参数,返回 {@link OptionalDouble} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalDouble
- * @see Function
- */
-@FunctionalInterface
-public interface ToOptionalDoubleFunction extends Function {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalIntFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalIntFunction.java
deleted file mode 100644
index 5cb479e..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalIntFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalInt;
-import java.util.function.Function;
-
-/**
- * ToOptionalIntFunction
- *
- *
- * 接受类型为 T 的参数,返回 {@link OptionalInt} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalInt
- * @see Function
- */
-@FunctionalInterface
-public interface ToOptionalIntFunction extends Function {
-}
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalLongFunction.java b/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalLongFunction.java
deleted file mode 100644
index d197173..0000000
--- a/src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalLongFunction.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2023-2024 the original author or 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
- *
- * https://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 xyz.zhouxy.plusone.commons.function;
-
-import java.util.OptionalLong;
-import java.util.function.Function;
-
-/**
- * ToOptionalLongFunction
- *
- *
- * 接受类型为 T 的参数,返回 {@link OptionalLong} 对象。
- *
- * @author ZhouXY
- * @since 0.1.0
- * @see OptionalLong
- * @see Function
- */
-@FunctionalInterface
-public interface ToOptionalLongFunction extends Function {
-}