Merge branch 'upstream'

Author: virtuald

commands2/src/include/frc2/command/CommandBase.h

@@ -26,27 +26,55 @@ class CommandBase : public Command,
   /**
    * Adds the specified Subsystem requirements to the command.
    *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
    * @param requirements the Subsystem requirements to add
    */
   void AddRequirements(std::initializer_list<std::shared_ptr<Subsystem>> requirements);
 
   /**
    * Adds the specified Subsystem requirements to the command.
    *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
    * @param requirements the Subsystem requirements to add
    */
   void AddRequirements(std::span<std::shared_ptr<Subsystem>> requirements);
 
   /**
    * Adds the specified Subsystem requirements to the command.
    *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
    * @param requirements the Subsystem requirements to add
    */
   void AddRequirements(wpi::SmallSet<std::shared_ptr<Subsystem>, 4> requirements);
 
   /**
    * Adds the specified Subsystem requirement to the command.
    *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
    * @param requirement the Subsystem requirement to add
    */
   void AddRequirements(std::shared_ptr<Subsystem> requirement);