find some instances where THROW_IF is more natural

Author: AlexandreAmice

common/drake_throw.h

@@ -34,8 +34,7 @@ namespace internal {
 #define DRAKE_THROW_UNLESS(condition)                                         \
   do {                                                                        \
     typedef ::drake::assert::ConditionTraits<                                 \
-        typename std::remove_cv_t<decltype(condition)>>                       \
-        Trait;                                                                \
+        typename std::remove_cv_t<decltype(condition)>> Trait;                \
     static_assert(Trait::is_valid, "Condition should be bool-convertible.");  \
     static_assert(                                                            \
         !std::is_pointer_v<decltype(condition)>,                              \
@@ -49,4 +48,4 @@ namespace internal {
 
 /// Provides the same behavior as DRAKE_THROW_UNLESS, except that it throws an
 /// exception iff the value is true.
-#define DRAKE_THROW_IF(condition) DRAKE_THROW_UNLESS(!condition)
+#define DRAKE_THROW_IF(condition) DRAKE_THROW_UNLESS(!(condition))

geometry/meshcat.cc

@@ -769,8 +769,8 @@ class Meshcat::Impl {
         main_thread_id_(std::this_thread::get_id()),
         params_(params),
         rate_calculator_(params_.realtime_rate_period) {
-    DRAKE_THROW_UNLESS(!params.port.has_value() || *params.port == 0 ||
-                       *params.port >= 1024);
+    DRAKE_THROW_IF(params.port.has_value() && *params.port == 0 &&
+                   *params.port >= 1024);
     if (!drake::internal::IsNetworkingAllowed("meshcat")) {
       throw std::runtime_error(
           "Meshcat has been disabled via the DRAKE_ALLOW_NETWORK environment "

geometry/optimization/hpolyhedron.cc

@@ -919,7 +919,7 @@ HPolyhedron HPolyhedron::SimplifyByIncrementalFaceTranslation(
   const HPolyhedron circumbody = this->ReduceInequalities(0);
   MatrixXd circumbody_A = circumbody.A();
   VectorXd circumbody_b = circumbody.b();
-  DRAKE_THROW_UNLESS(!circumbody.IsEmpty());
+  DRAKE_THROW_IF(circumbody.IsEmpty());
   DRAKE_THROW_UNLESS(circumbody.IsBounded());
 
   for (int i = 0; i < points_to_contain.cols(); ++i) {

geometry/proximity/volume_mesh_refiner.cc

@@ -181,7 +181,7 @@ void VolumeMeshRefiner::CutTetrahedron(const int tetrahedron,
 
 std::vector<int> VolumeMeshRefiner::GetTetrahedraOnTriangle(int v0, int v1,
                                                             int v2) const {
-  DRAKE_THROW_UNLESS(v0 != v1 && v1 != v2 && v2 != v0);
+  DRAKE_THROW_IF(v0 == v1 || v1 == v2 || v2 == v0);
   std::vector<int> incident_tetrahedra;
   const std::vector<int>& tetrahedra0 = vertex_to_tetrahedra_[v0];
   const std::vector<int>& tetrahedra1 = vertex_to_tetrahedra_[v1];

multibody/plant/multibody_plant.cc

@@ -779,7 +779,7 @@ MultibodyConstraintId MultibodyPlant<T>::AddTendonConstraint(
     upper_limit = kInf;
   }
 
-  DRAKE_THROW_UNLESS(*lower_limit != -kInf || *upper_limit != kInf);
+  DRAKE_THROW_IF(*lower_limit == -kInf && *upper_limit == kInf);
   DRAKE_THROW_UNLESS(*lower_limit <= *upper_limit);
 
   if (stiffness.has_value()) {

multibody/tree/multibody_tree_topology.cc

@@ -225,7 +225,7 @@ JointActuatorIndex MultibodyTreeTopology::add_joint_actuator(int num_dofs) {
 void MultibodyTreeTopology::RemoveJointActuator(
     JointActuatorIndex actuator_index) {
   DRAKE_DEMAND(actuator_index < ssize(joint_actuators_));
-  DRAKE_THROW_UNLESS(!is_valid());
+  DRAKE_THROW_IF(is_valid());
   DRAKE_THROW_UNLESS(joint_actuators_[actuator_index].has_value());
 
   // Reduce the total number of actuated dofs.