[wpimath] Make geometry classes constexpr (#7222)

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

@@ -11,6 +11,7 @@
 #include "units/math.h"
 
 namespace frc {
+
 /**
  * A change in distance along a 2D arc since the last pose update. We can use
  * ideas from differential calculus to create new Pose2ds from a Twist2d and
@@ -40,7 +41,7 @@ struct WPILIB_DLLEXPORT Twist2d {
    * @param other The other object.
    * @return Whether the two objects are equal.
    */
-  bool operator==(const Twist2d& other) const {
+  constexpr bool operator==(const Twist2d& other) const {
     return units::math::abs(dx - other.dx) < 1E-9_m &&
            units::math::abs(dy - other.dy) < 1E-9_m &&
            units::math::abs(dtheta - other.dtheta) < 1E-9_rad;
@@ -56,6 +57,7 @@ struct WPILIB_DLLEXPORT Twist2d {
     return Twist2d{dx * factor, dy * factor, dtheta * factor};
   }
 };
+
 }  // namespace frc
 
 #ifndef NO_PROTOBUF