Change C++ WaitCommand to use units (#1865)

Also remove unique_ptr usage.

wpilibc/src/main/native/cpp/frc2/command/Command.cpp

@@ -28,9 +28,9 @@ void Command::Initialize() {}
 void Command::Execute() {}
 void Command::End(bool interrupted) {}
 
-ParallelRaceGroup Command::WithTimeout(double seconds) && {
+ParallelRaceGroup Command::WithTimeout(units::second_t duration) && {
   std::vector<std::unique_ptr<Command>> temp;
-  temp.emplace_back(std::make_unique<WaitCommand>(seconds));
+  temp.emplace_back(std::make_unique<WaitCommand>(duration));
   temp.emplace_back(std::move(*this).TransferOwnership());
   return ParallelRaceGroup(std::move(temp));
 }

wpilibc/src/main/native/cpp/frc2/command/WaitCommand.cpp

@@ -9,19 +9,18 @@
 
 using namespace frc2;
 
-WaitCommand::WaitCommand(double seconds) : m_duration{seconds} {
-  auto secondsStr = std::to_string(seconds);
-  SetName(wpi::Twine(m_name) + ": " + wpi::Twine(secondsStr) + " seconds");
-  m_timer = std::make_unique<frc::Timer>();
+WaitCommand::WaitCommand(units::second_t duration) : m_duration{duration} {
+  auto durationStr = std::to_string(duration.to<double>());
+  SetName(wpi::Twine(m_name) + ": " + wpi::Twine(durationStr) + " seconds");
 }
 
 void WaitCommand::Initialize() {
-  m_timer->Reset();
-  m_timer->Start();
+  m_timer.Reset();
+  m_timer.Start();
 }
 
-void WaitCommand::End(bool interrupted) { m_timer->Stop(); }
+void WaitCommand::End(bool interrupted) { m_timer.Stop(); }
 
-bool WaitCommand::IsFinished() { return m_timer->HasPeriodPassed(m_duration); }
+bool WaitCommand::IsFinished() { return m_timer.HasPeriodPassed(m_duration); }
 
 bool WaitCommand::RunsWhenDisabled() const { return true; }

wpilibc/src/main/native/include/frc2/command/Command.h

@@ -14,6 +14,7 @@
 #include <memory>
 #include <string>
 
+#include <units/units.h>
 #include <wpi/ArrayRef.h>
 #include <wpi/Demangle.h>
 #include <wpi/SmallSet.h>
@@ -103,10 +104,10 @@ class Command : public frc::ErrorBase {
    * interrupted and un-scheduled.  Note that the timeout only applies to the
    * command returned by this method; the calling command is not itself changed.
    *
-   * @param seconds the timeout duration
+   * @param duration the timeout duration
    * @return the command with the timeout added
    */
-  ParallelRaceGroup WithTimeout(double seconds) &&;
+  ParallelRaceGroup WithTimeout(units::second_t duration) &&;
 
   /**
    * Decorates this command with an interrupt condition.  If the specified

wpilibc/src/main/native/include/frc2/command/WaitCommand.h

@@ -7,8 +7,7 @@
 
 #pragma once
 
-#include <memory>
-
+#include <units/units.h>
 #include <wpi/Twine.h>
 
 #include "CommandBase.h"
@@ -27,9 +26,9 @@ class WaitCommand : public CommandHelper<CommandBase, WaitCommand> {
    * Creates a new WaitCommand.  This command will do nothing, and end after the
    * specified duration.
    *
-   * @param seconds the time to wait, in seconds
+   * @param duration the time to wait
    */
-  explicit WaitCommand(double seconds);
+  explicit WaitCommand(units::second_t duration);
 
   WaitCommand(WaitCommand&& other) = default;
 
@@ -44,9 +43,9 @@ class WaitCommand : public CommandHelper<CommandBase, WaitCommand> {
   bool RunsWhenDisabled() const override;
 
  protected:
-  std::unique_ptr<frc::Timer> m_timer;
+  frc::Timer m_timer;
 
  private:
-  double m_duration;
+  units::second_t m_duration;
 };
 }  // namespace frc2