Use defaulted comparison operators in C++ (#4723)

Comparison operators which compared against every class member variable
now use C++20's default comparison operators.

Also remove operator!= that in C++20 is now auto-generated from operator==.

wpimath/src/main/native/cpp/geometry/Pose2d.cpp

@@ -15,14 +15,6 @@ Transform2d Pose2d::operator-(const Pose2d& other) const {
   return Transform2d{pose.Translation(), pose.Rotation()};
 }
 
-bool Pose2d::operator==(const Pose2d& other) const {
-  return m_translation == other.m_translation && m_rotation == other.m_rotation;
-}
-
-bool Pose2d::operator!=(const Pose2d& other) const {
-  return !operator==(other);
-}
-
 Pose2d Pose2d::RelativeTo(const Pose2d& other) const {
   const Transform2d transform{other, *this};
   return {transform.Translation(), transform.Rotation()};

wpimath/src/main/native/cpp/geometry/Pose3d.cpp

@@ -52,14 +52,6 @@ Transform3d Pose3d::operator-(const Pose3d& other) const {
   return Transform3d{pose.Translation(), pose.Rotation()};
 }
 
-bool Pose3d::operator==(const Pose3d& other) const {
-  return m_translation == other.m_translation && m_rotation == other.m_rotation;
-}
-
-bool Pose3d::operator!=(const Pose3d& other) const {
-  return !operator==(other);
-}
-
 Pose3d Pose3d::operator*(double scalar) const {
   return Pose3d{m_translation * scalar, m_rotation * scalar};
 }

wpimath/src/main/native/cpp/geometry/Quaternion.cpp

@@ -33,10 +33,6 @@ bool Quaternion::operator==(const Quaternion& other) const {
   return std::abs(m_r * other.m_r + m_v.dot(other.m_v)) > 1.0 - 1E-9;
 }
 
-bool Quaternion::operator!=(const Quaternion& other) const {
-  return !operator==(other);
-}
-
 Quaternion Quaternion::Inverse() const {
   return Quaternion{m_r, -m_v(0), -m_v(1), -m_v(2)};
 }

wpimath/src/main/native/cpp/geometry/Rotation3d.cpp

@@ -170,14 +170,6 @@ Rotation3d Rotation3d::operator/(double scalar) const {
   return *this * (1.0 / scalar);
 }
 
-bool Rotation3d::operator==(const Rotation3d& other) const {
-  return m_q == other.m_q;
-}
-
-bool Rotation3d::operator!=(const Rotation3d& other) const {
-  return !operator==(other);
-}
-
 Rotation3d Rotation3d::RotateBy(const Rotation3d& other) const {
   return Rotation3d{other.m_q * m_q};
 }

wpimath/src/main/native/cpp/geometry/Transform2d.cpp

@@ -21,11 +21,3 @@ Transform2d::Transform2d(Pose2d initial, Pose2d final) {
 Transform2d Transform2d::operator+(const Transform2d& other) const {
   return Transform2d{Pose2d{}, Pose2d{}.TransformBy(*this).TransformBy(other)};
 }
-
-bool Transform2d::operator==(const Transform2d& other) const {
-  return m_translation == other.m_translation && m_rotation == other.m_rotation;
-}
-
-bool Transform2d::operator!=(const Transform2d& other) const {
-  return !operator==(other);
-}

wpimath/src/main/native/cpp/geometry/Transform3d.cpp

@@ -31,11 +31,3 @@ Transform3d Transform3d::Inverse() const {
 Transform3d Transform3d::operator+(const Transform3d& other) const {
   return Transform3d{Pose3d{}, Pose3d{}.TransformBy(*this).TransformBy(other)};
 }
-
-bool Transform3d::operator==(const Transform3d& other) const {
-  return m_translation == other.m_translation && m_rotation == other.m_rotation;
-}
-
-bool Transform3d::operator!=(const Transform3d& other) const {
-  return !operator==(other);
-}

wpimath/src/main/native/cpp/geometry/Translation2d.cpp

@@ -23,10 +23,6 @@ bool Translation2d::operator==(const Translation2d& other) const {
          units::math::abs(m_y - other.m_y) < 1E-9_m;
 }
 
-bool Translation2d::operator!=(const Translation2d& other) const {
-  return !operator==(other);
-}
-
 void frc::to_json(wpi::json& json, const Translation2d& translation) {
   json =
       wpi::json{{"x", translation.X().value()}, {"y", translation.Y().value()}};

wpimath/src/main/native/cpp/geometry/Translation3d.cpp

@@ -41,10 +41,6 @@ bool Translation3d::operator==(const Translation3d& other) const {
          units::math::abs(m_z - other.m_z) < 1E-9_m;
 }
 
-bool Translation3d::operator!=(const Translation3d& other) const {
-  return !operator==(other);
-}
-
 void frc::to_json(wpi::json& json, const Translation3d& translation) {
   json = wpi::json{{"x", translation.X().value()},
                    {"y", translation.Y().value()},

wpimath/src/main/native/cpp/trajectory/Trajectory.cpp

@@ -13,16 +13,6 @@
 
 using namespace frc;
 
-bool Trajectory::State::operator==(const Trajectory::State& other) const {
-  return t == other.t && velocity == other.velocity &&
-         acceleration == other.acceleration && pose == other.pose &&
-         curvature == other.curvature;
-}
-
-bool Trajectory::State::operator!=(const Trajectory::State& other) const {
-  return !operator==(other);
-}
-
 Trajectory::State Trajectory::State::Interpolate(State endValue,
                                                  double i) const {
   // Find the new [t] value.
@@ -163,11 +153,3 @@ void frc::from_json(const wpi::json& json, Trajectory::State& state) {
       units::meters_per_second_squared_t{json.at("acceleration").get<double>()};
   state.curvature = units::curvature_t{json.at("curvature").get<double>()};
 }
-
-bool Trajectory::operator==(const Trajectory& other) const {
-  return m_states == other.States();
-}
-
-bool Trajectory::operator!=(const Trajectory& other) const {
-  return !operator==(other);
-}

wpimath/src/main/native/include/frc/geometry/Pose2d.h

@@ -70,19 +70,8 @@ class WPILIB_DLLEXPORT Pose2d {
 
   /**
    * Checks equality between this Pose2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Pose2d& other) const;
-
-  /**
-   * Checks inequality between this Pose2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Pose2d& other) const;
+  bool operator==(const Pose2d&) const = default;
 
   /**
    * Returns the underlying translation.

wpimath/src/main/native/include/frc/geometry/Pose3d.h

@@ -74,19 +74,8 @@ class WPILIB_DLLEXPORT Pose3d {
 
   /**
    * Checks equality between this Pose3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Pose3d& other) const;
-
-  /**
-   * Checks inequality between this Pose3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Pose3d& other) const;
+  bool operator==(const Pose3d&) const = default;
 
   /**
    * Returns the underlying translation.

wpimath/src/main/native/include/frc/geometry/Quaternion.h

@@ -46,14 +46,6 @@ class WPILIB_DLLEXPORT Quaternion {
    */
   bool operator==(const Quaternion& other) const;
 
-  /**
-   * Checks inequality between this Quaternion and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Quaternion& other) const;
-
   /**
    * Returns the inverse of the quaternion.
    */

wpimath/src/main/native/include/frc/geometry/Rotation2d.h

@@ -108,14 +108,6 @@ class WPILIB_DLLEXPORT Rotation2d {
    */
   constexpr bool operator==(const Rotation2d& other) const;
 
-  /**
-   * Checks inequality between this Rotation2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  constexpr bool operator!=(const Rotation2d& other) const;
-
   /**
    * Adds the new rotation to the current rotation using a rotation matrix.
    *

wpimath/src/main/native/include/frc/geometry/Rotation2d.inc

@@ -58,10 +58,6 @@ constexpr bool Rotation2d::operator==(const Rotation2d& other) const {
               : std::hypot(Cos() - other.Cos(), Sin() - other.Sin())) < 1E-9;
 }
 
-constexpr bool Rotation2d::operator!=(const Rotation2d& other) const {
-  return !operator==(other);
-}
-
 constexpr Rotation2d Rotation2d::RotateBy(const Rotation2d& other) const {
   return {Cos() * other.Cos() - Sin() * other.Sin(),
           Cos() * other.Sin() + Sin() * other.Cos()};

wpimath/src/main/native/include/frc/geometry/Rotation3d.h

@@ -125,19 +125,8 @@ class WPILIB_DLLEXPORT Rotation3d {
 
   /**
    * Checks equality between this Rotation3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Rotation3d& other) const;
-
-  /**
-   * Checks inequality between this Rotation3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Rotation3d& other) const;
+  bool operator==(const Rotation3d&) const = default;
 
   /**
    * Adds the new rotation to the current rotation.

wpimath/src/main/native/include/frc/geometry/Transform2d.h

@@ -103,19 +103,8 @@ class WPILIB_DLLEXPORT Transform2d {
 
   /**
    * Checks equality between this Transform2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Transform2d& other) const;
-
-  /**
-   * Checks inequality between this Transform2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Transform2d& other) const;
+  bool operator==(const Transform2d&) const = default;
 
  private:
   Translation2d m_translation;

wpimath/src/main/native/include/frc/geometry/Transform3d.h

@@ -108,19 +108,8 @@ class WPILIB_DLLEXPORT Transform3d {
 
   /**
    * Checks equality between this Transform3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Transform3d& other) const;
-
-  /**
-   * Checks inequality between this Transform3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Transform3d& other) const;
+  bool operator==(const Transform3d&) const = default;
 
  private:
   Translation3d m_translation;

wpimath/src/main/native/include/frc/geometry/Translation2d.h

@@ -170,14 +170,6 @@ class WPILIB_DLLEXPORT Translation2d {
    */
   bool operator==(const Translation2d& other) const;
 
-  /**
-   * Checks inequality between this Translation2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Translation2d& other) const;
-
  private:
   units::meter_t m_x = 0_m;
   units::meter_t m_y = 0_m;

wpimath/src/main/native/include/frc/geometry/Translation3d.h

@@ -172,14 +172,6 @@ class WPILIB_DLLEXPORT Translation3d {
    */
   bool operator==(const Translation3d& other) const;
 
-  /**
-   * Checks inequality between this Translation3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Translation3d& other) const;
-
  private:
   units::meter_t m_x = 0_m;
   units::meter_t m_y = 0_m;

wpimath/src/main/native/include/frc/geometry/Twist2d.h

@@ -46,14 +46,6 @@ struct WPILIB_DLLEXPORT Twist2d {
            units::math::abs(dtheta - other.dtheta) < 1E-9_rad;
   }
 
-  /**
-   * Checks inequality between this Twist2d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Twist2d& other) const { return !operator==(other); }
-
   /**
    * Scale this by a given factor.
    *

wpimath/src/main/native/include/frc/geometry/Twist3d.h

@@ -65,14 +65,6 @@ struct WPILIB_DLLEXPORT Twist3d {
            units::math::abs(rz - other.rz) < 1E-9_rad;
   }
 
-  /**
-   * Checks inequality between this Twist3d and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are not equal.
-   */
-  bool operator!=(const Twist3d& other) const { return !operator==(other); }
-
   /**
    * Scale this by a given factor.
    *

wpimath/src/main/native/include/frc/trajectory/Trajectory.h

@@ -48,19 +48,8 @@ class WPILIB_DLLEXPORT Trajectory {
 
     /**
      * Checks equality between this State and another object.
-     *
-     * @param other The other object.
-     * @return Whether the two objects are equal.
      */
-    bool operator==(const State& other) const;
-
-    /**
-     * Checks inequality between this State and another object.
-     *
-     * @param other The other object.
-     * @return Whether the two objects are not equal.
-     */
-    bool operator!=(const State& other) const;
+    bool operator==(const State&) const = default;
 
     /**
      * Interpolates between two States.
@@ -140,19 +129,8 @@ class WPILIB_DLLEXPORT Trajectory {
 
   /**
    * Checks equality between this Trajectory and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are equal.
    */
-  bool operator==(const Trajectory& other) const;
-
-  /**
-   * Checks inequality between this Trajectory and another object.
-   *
-   * @param other The other object.
-   * @return Whether the two objects are inequal.
-   */
-  bool operator!=(const Trajectory& other) const;
+  bool operator==(const Trajectory&) const = default;
 
  private:
   std::vector<State> m_states;

wpimath/src/main/native/include/frc/trajectory/TrapezoidProfile.h

@@ -68,10 +68,7 @@ class TrapezoidProfile {
    public:
     Distance_t position{0};
     Velocity_t velocity{0};
-    bool operator==(const State& rhs) const {
-      return position == rhs.position && velocity == rhs.velocity;
-    }
-    bool operator!=(const State& rhs) const { return !(*this == rhs); }
+    bool operator==(const State&) const = default;
   };
 
   /**