implement unique function to use as base for task

source/fiber/sched/task/unique_function.hpp

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "task.hpp"
+
+#include <memory>
+#include <utility>
+
+namespace fiber::sched::task {
+
+template <typename F>
+class UniqueFunction : TaskBase {
+ public:
+  static TaskBase* New(F&& func) {
+    return new UniqueFunction(std::move(func));
+  }
+
+  // Movable
+
+  UniqueFunction(UniqueFunction&& other) noexcept
+      : func_(std::move(other.func_)) {
+  }
+
+  UniqueFunction& operator=(UniqueFunction&& other) noexcept {
+    if (this != &other) {
+      func_ = std::move(other.func_);
+    }
+
+    return *this;
+  }
+
+  // Non-copyable
+  UniqueFunction(const UniqueFunction&&) = delete;
+  UniqueFunction& operator=(const UniqueFunction&&) = delete;
+
+  void Run() noexcept override {
+    func_();
+    delete this;
+  }
+
+  virtual ~UniqueFunction() = default;
+
+ private:
+  explicit UniqueFunction(F&& func)
+      : func_(std::move(func)) {
+  }
+
+ private:
+  F func_;
+};
+
+}  // namespace fiber::sched::task