[commands] Add RepeatCommand (#4009)

Co-authored-by: Starlight220 <53231611+Starlight220@users.noreply.github.com>

wpilibNewCommands/src/main/native/include/frc2/command/RepeatCommand.h

@@ -0,0 +1,81 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#ifdef _WIN32
+#pragma warning(push)
+#pragma warning(disable : 4521)
+#endif
+
+#include <memory>
+#include <utility>
+
+#include "frc2/command/CommandBase.h"
+#include "frc2/command/CommandGroupBase.h"
+#include "frc2/command/CommandHelper.h"
+
+namespace frc2 {
+/**
+ * A command that runs another command repeatedly, restarting it when it ends,
+ * until this command is interrupted. While this class does not extend {@link
+ * CommandGroupBase}, it is still considered a CommandGroup, as it allows one to
+ * compose another command within it; the command instances that are passed to
+ * it cannot be added to any other groups, or scheduled individually.
+ *
+ * <p>As a rule, CommandGroups require the union of the requirements of their
+ * component commands.
+ *
+ * <p>This class is provided by the NewCommands VendorDep
+ */
+class RepeatCommand : public CommandHelper<CommandBase, RepeatCommand> {
+ public:
+  /**
+   * Creates a new RepeatCommand. Will run another command repeatedly,
+   * restarting it whenever it ends, until this command is interrupted.
+   *
+   * @param command the command to run repeatedly
+   */
+  explicit RepeatCommand(std::unique_ptr<Command>&& command);
+
+  /**
+   * Creates a new RepeatCommand. Will run another command repeatedly,
+   * restarting it whenever it ends, until this command is interrupted.
+   *
+   * @param command the command to run repeatedly
+   */
+  template <class T, typename = std::enable_if_t<std::is_base_of_v<
+                         Command, std::remove_reference_t<T>>>>
+  explicit RepeatCommand(T&& command)
+      : RepeatCommand(std::make_unique<std::remove_reference_t<T>>(
+            std::forward<T>(command))) {}
+
+  RepeatCommand(RepeatCommand&& other) = default;
+
+  // No copy constructors for command groups
+  RepeatCommand(const RepeatCommand& other) = delete;
+
+  // Prevent template expansion from emulating copy ctor
+  RepeatCommand(RepeatCommand&) = delete;
+
+  void Initialize() override;
+
+  void Execute() override;
+
+  bool IsFinished() override;
+
+  void End(bool interrupted) override;
+
+  bool RunsWhenDisabled() const override;
+
+  RepeatCommand Repeat() && override;
+
+ private:
+  std::unique_ptr<Command> m_command;
+};
+}  // namespace frc2
+
+#ifdef _WIN32
+#pragma warning(pop)
+#endif