[commands] Revert SubsystemBase deprecation/removal (#5634)

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

@@ -6,11 +6,8 @@
 
 #include <concepts>
 #include <functional>
-#include <string>
 #include <utility>
 
-#include <wpi/sendable/Sendable.h>
-
 #include "frc2/command/CommandScheduler.h"
 
 namespace frc2 {
@@ -27,19 +24,22 @@ class CommandPtr;
  * subsystem should generally remain encapsulated and not be shared by other
  * parts of the robot.
  *
- * <p>Subsystems are automatically registered with the scheduler with the
+ * <p>Subsystems must be registered with the scheduler with the
  * CommandScheduler.RegisterSubsystem() method in order for the
- * Periodic() method to be called.
+ * Periodic() method to be called.  It is recommended that this method be called
+ * from the constructor of users' Subsystem implementations.  The
+ * SubsystemBase class offers a simple base for user implementations
+ * that handles this.
  *
  * This class is provided by the NewCommands VendorDep
  *
  * @see Command
  * @see CommandScheduler
+ * @see SubsystemBase
  */
-class Subsystem : public wpi::Sendable, public wpi::SendableHelper<Subsystem> {
+class Subsystem {
  public:
-  ~Subsystem() override;
-
+  virtual ~Subsystem();
   /**
    * This method is called periodically by the CommandScheduler.  Useful for
    * updating subsystem-specific state that you don't want to offload to a
@@ -111,43 +111,6 @@ class Subsystem : public wpi::Sendable, public wpi::SendableHelper<Subsystem> {
    */
   void Register();
 
-  /**
-   * Gets the name of this Subsystem.
-   *
-   * @return Name
-   */
-  std::string GetName() const;
-
-  /**
-   * Sets the name of this Subsystem.
-   *
-   * @param name name
-   */
-  void SetName(std::string_view name);
-
-  /**
-   * Gets the subsystem name of this Subsystem.
-   *
-   * @return Subsystem name
-   */
-  std::string GetSubsystem() const;
-
-  /**
-   * Sets the subsystem name of this Subsystem.
-   *
-   * @param name subsystem name
-   */
-  void SetSubsystem(std::string_view name);
-
-  /**
-   * Associate a Sendable with this Subsystem.
-   * Also update the child's name.
-   *
-   * @param name name to give child
-   * @param child sendable
-   */
-  void AddChild(std::string name, wpi::Sendable* child);
-
   /**
    * Constructs a command that runs an action once and finishes. Requires this
    * subsystem.
@@ -185,10 +148,5 @@ class Subsystem : public wpi::Sendable, public wpi::SendableHelper<Subsystem> {
    */
   [[nodiscard]]
   CommandPtr RunEnd(std::function<void()> run, std::function<void()> end);
-
-  void InitSendable(wpi::SendableBuilder& builder) override;
-
- protected:
-  Subsystem();
 };
 }  // namespace frc2