[core] Pass and return fundamental types by value instead of const ref.

core/include/jiminy/core/engine/system.h

@@ -18,7 +18,6 @@ namespace jiminy
     class AbstractController;
     class LockGuardLocal;
 
-
     // External force functors
     using ForceProfileFunctor = std::function<pinocchio::Force(
         float64_t /*t*/, const Eigen::VectorXd & /*q*/, const Eigen::VectorXd & /*v*/)>;

core/include/jiminy/core/hardware/abstract_motor.h

@@ -16,7 +16,6 @@
 namespace jiminy
 {
     class Robot;
-
     class AbstractMotorBase;
 
     /// \brief Structure holding the data for every motor.
@@ -123,7 +122,7 @@ namespace jiminy
         const std::string & getName() const;
 
         /// \brief Index of the motor.
-        const std::size_t & getIdx() const;
+        std::size_t getIdx() const;
 
         /// \brief Name of the joint associated with the motor.
         const std::string & getJointName() const;

core/include/jiminy/core/hardware/abstract_sensor.h

@@ -19,7 +19,6 @@ namespace jiminy
 {
     class TelemetryData;
     class Robot;
-
     class AbstractSensorBase;
 
     // Sensor data holder
@@ -286,7 +285,7 @@ namespace jiminy
         const std::string & getName() const;
 
         /// \brief Index of the sensor of the global shared buffer.
-        virtual const std::size_t & getIdx() const = 0;
+        virtual std::size_t getIdx() const = 0;
 
         /// \brief Type of the sensor.
         virtual const std::string & getType() const = 0;
@@ -420,7 +419,7 @@ namespace jiminy
         void updateTelemetryAll() override final;
 
         virtual hresult_t setOptionsAll(const GenericConfig & sensorOptions) override final;
-        virtual const std::size_t & getIdx() const override final;
+        virtual std::size_t getIdx() const override final;
         virtual const std::string & getType() const override final;
         virtual const std::vector<std::string> & getFieldnames() const final;
         virtual uint64_t getSize() const override final;

core/include/jiminy/core/hardware/abstract_sensor.hxx

@@ -237,7 +237,7 @@ namespace jiminy
     }
 
     template<typename T>
-    const std::size_t & AbstractSensorTpl<T>::getIdx() const
+    std::size_t AbstractSensorTpl<T>::getIdx() const
     {
         return sensorIdx_;
     }

core/include/jiminy/core/hardware/basic_sensors.h

@@ -172,7 +172,7 @@ namespace jiminy
         virtual hresult_t refreshProxies() final override;
 
         const std::string & getMotorName() const;
-        const std::size_t & getMotorIdx() const;
+        std::size_t getMotorIdx() const;
 
     private:
         virtual hresult_t set(float64_t t,

core/src/constraints/frame_constraint.cc

@@ -180,7 +180,7 @@ namespace jiminy
         // Extract masked jacobian and drift, only containing fixed dofs
         for (uint32_t i = 0; i < dofsFixed_.size(); ++i)
         {
-            uint32_t dofIndex = dofsFixed_[i];
+            const uint32_t dofIndex = dofsFixed_[i];
             jacobian_.row(i) = frameJacobian_.row(dofIndex);
             drift_[i] = frameDrift_.toVector()[dofIndex];
         }

core/src/hardware/abstract_motor.cc

@@ -160,23 +160,24 @@ namespace jiminy
         if (isInitialized_)
         {
             // Check if armature has changed
-            bool_t enableArmature = boost::get<bool_t>(motorOptions.at("enableArmature"));
+            const bool_t enableArmature = boost::get<bool_t>(motorOptions.at("enableArmature"));
             internalBuffersMustBeUpdated |= (baseMotorOptions_->enableArmature != enableArmature);
             if (enableArmature)
             {
-                float64_t armature = boost::get<float64_t>(motorOptions.at("armature"));
+                const float64_t armature = boost::get<float64_t>(motorOptions.at("armature"));
                 internalBuffersMustBeUpdated |=  //
                     std::abs(armature - baseMotorOptions_->armature) > EPS;
             }
 
             // Check if command limit has changed
-            bool_t commandLimitFromUrdf =
+            const bool_t commandLimitFromUrdf =
                 boost::get<bool_t>(motorOptions.at("commandLimitFromUrdf"));
             internalBuffersMustBeUpdated |=
                 (baseMotorOptions_->commandLimitFromUrdf != commandLimitFromUrdf);
             if (!commandLimitFromUrdf)
             {
-                float64_t commandLimit = boost::get<float64_t>(motorOptions.at("commandLimit"));
+                const float64_t commandLimit =
+                    boost::get<float64_t>(motorOptions.at("commandLimit"));
                 internalBuffersMustBeUpdated |=
                     std::abs(commandLimit - baseMotorOptions_->commandLimit) > EPS;
             }
@@ -353,7 +354,7 @@ namespace jiminy
         return name_;
     }
 
-    const std::size_t & AbstractMotorBase::getIdx() const
+    std::size_t AbstractMotorBase::getIdx() const
     {
         return motorIdx_;
     }

core/src/hardware/basic_motors.cc

@@ -104,18 +104,17 @@ namespace jiminy
            It is computed on joint side instead of the motor. */
         if (motorOptions_->enableFriction)
         {
-            float64_t vJoint = v;
-            if (vJoint > 0)
+            if (v > 0)
             {
-                data() += motorOptions_->frictionViscousPositive * vJoint +
-                          motorOptions_->frictionDryPositive *
-                              tanh(motorOptions_->frictionDrySlope * vJoint);
+                data() +=
+                    motorOptions_->frictionViscousPositive * v +
+                    motorOptions_->frictionDryPositive * tanh(motorOptions_->frictionDrySlope * v);
             }
             else
             {
-                data() += motorOptions_->frictionViscousNegative * vJoint +
-                          motorOptions_->frictionDryNegative *
-                              tanh(motorOptions_->frictionDrySlope * vJoint);
+                data() +=
+                    motorOptions_->frictionViscousNegative * v +
+                    motorOptions_->frictionDryNegative * tanh(motorOptions_->frictionDrySlope * v);
             }
         }
 

core/src/hardware/basic_sensors.cc

@@ -386,7 +386,7 @@ namespace jiminy
         GET_ROBOT_IF_INITIALIZED()
 
         // Get the sum of external forces applied on parent joint
-        pinocchio::JointIndex i = parentJointIdx_;
+        const pinocchio::JointIndex i = parentJointIdx_;
         const pinocchio::Force & fJoint = fExternal[i];
 
         // Transform the force from joint frame to sensor frame
@@ -489,12 +489,12 @@ namespace jiminy
         GET_ROBOT_IF_INITIALIZED()
 
         const auto & joint = robot->pncModel_.joints[jointIdx_];
-        int32_t jointPositionIdx = joint.idx_q();
-        int32_t jointVelocityIdx = joint.idx_v();
+        const int32_t jointPositionIdx = joint.idx_q();
+        const int32_t jointVelocityIdx = joint.idx_v();
         if (jointType_ == JointModelType::ROTARY_UNBOUNDED)
         {
-            float64_t cosTheta = q[jointPositionIdx];
-            float64_t sinTheta = q[jointPositionIdx + 1];
+            const float64_t cosTheta = q[jointPositionIdx];
+            const float64_t sinTheta = q[jointPositionIdx + 1];
             data()[0] = std::atan2(sinTheta, cosTheta);
         }
         else
@@ -564,7 +564,7 @@ namespace jiminy
         return motorName_;
     }
 
-    const std::size_t & EffortSensor::getMotorIdx() const
+    std::size_t EffortSensor::getMotorIdx() const
     {
         return motorIdx_;
     }

core/src/robot/model.cc

@@ -1159,10 +1159,11 @@ namespace jiminy
 
             for (const std::string & jointName : rigidJointsNames_)
             {
-                pinocchio::JointIndex jointIdx = pncModel_.getJointId(jointName);
+                const pinocchio::JointIndex jointIdx = pncModel_.getJointId(jointName);
 
                 // Add bias to com position
-                float64_t comBiasStd = mdlOptions_->dynamics.centerOfMassPositionBodiesBiasStd;
+                const float64_t comBiasStd =
+                    mdlOptions_->dynamics.centerOfMassPositionBodiesBiasStd;
                 if (comBiasStd > EPS)
                 {
                     Eigen::Vector3d & comRelativePositionBody =
@@ -1173,7 +1174,7 @@ namespace jiminy
 
                 /* Add bias to body mass.
                    It cannot be less than min(original mass, 1g) for numerical stability. */
-                float64_t massBiasStd = mdlOptions_->dynamics.massBodiesBiasStd;
+                const float64_t massBiasStd = mdlOptions_->dynamics.massBodiesBiasStd;
                 if (massBiasStd > EPS)
                 {
                     float64_t & massBody = pncModel_.inertias[jointIdx].mass();
@@ -1188,7 +1189,7 @@ namespace jiminy
                    small rotation is applied to the principal axes based on a randomly generated
                    rotation axis. Finally, the biased inertia matrix is obtained doing
                    `A @ diag(M) @ A.T`. If no bias, the original inertia matrix is recovered. */
-                float64_t inertiaBiasStd = mdlOptions_->dynamics.inertiaBodiesBiasStd;
+                const float64_t inertiaBiasStd = mdlOptions_->dynamics.inertiaBodiesBiasStd;
                 if (inertiaBiasStd > EPS)
                 {
                     pinocchio::Symmetric3 & inertiaBody = pncModel_.inertias[jointIdx].inertia();
@@ -1207,7 +1208,7 @@ namespace jiminy
                 }
 
                 // Add bias to relative body position (rotation excluded !)
-                float64_t relativeBodyPosBiasStd =
+                const float64_t relativeBodyPosBiasStd =
                     mdlOptions_->dynamics.relativePositionBodiesBiasStd;
                 if (relativeBodyPosBiasStd > EPS)
                 {
@@ -1813,7 +1814,7 @@ namespace jiminy
                                                               "centerOfMassPositionBodiesBiasStd",
                                                               "relativePositionBodiesBiasStd"}})
         {
-            float64_t value = boost::get<float64_t>(dynOptionsHolder.at(field));
+            const float64_t value = boost::get<float64_t>(dynOptionsHolder.at(field));
             if (0.9 < value || value < 0.0)
             {
                 PRINT_ERROR(

core/src/solver/constraint_solvers.cc

@@ -144,10 +144,10 @@ namespace jiminy
                 const ConstraintBlock & block = constraintData.blocks[i];
                 const Eigen::Index * fIdx = block.fIdx;
                 const std::uint_fast8_t & fSize = block.fSize;
-                Eigen::Index o = constraintData.startIdx;
+                const Eigen::Index o = constraintData.startIdx;
                 const Eigen::Index i0 = o + fIdx[0];
-                float64_t hi = block.hi;
-                float64_t lo = block.lo;
+                const float64_t hi = block.hi;
+                const float64_t lo = block.lo;
                 float64_t & e = x[i0];
 
                 // Bypass zero-ed coefficients
@@ -169,7 +169,7 @@ namespace jiminy
                 {
                     const Eigen::Index k = o + fIdx[j];
                     y_[k] = b[k] - A.col(k).dot(x);
-                    float64_t A_kk = A(k, k);
+                    const float64_t A_kk = A(k, k);
                     if (A_kk > A_max)
                     {
                         A_max = A_kk;
@@ -202,7 +202,7 @@ namespace jiminy
                         float64_t squaredNorm = e * e;
                         for (std::uint_fast8_t j = 1; j < fSize - 1; ++j)
                         {
-                            float64_t f = xConst[fIdx[j]];
+                            const float64_t f = xConst[fIdx[j]];
                             squaredNorm += f * f;
                         }
                         if (squaredNorm > thr * thr)

core/src/utilities/json.cc

@@ -263,7 +263,7 @@ namespace jiminy
                 }
                 else
                 {
-                    field = Eigen::VectorXd();
+                    field = Eigen::VectorXd{};
                 }
             }
             else

core/src/utilities/pinocchio.cc

@@ -32,7 +32,7 @@ namespace jiminy
              ++i)
         {
             // Get joint starting and ending index in position vector.
-            int32_t startIdx = model.joints[i].idx_q();
+            const int32_t startIdx = model.joints[i].idx_q();
             const int32_t endIdx = startIdx + model.joints[i].nq();
 
             // If idx is between start and end, we found the joint we were looking for.
@@ -55,7 +55,7 @@ namespace jiminy
              ++i)
         {
             // Get joint starting and ending index in velocity vector.
-            int32_t startIdx = model.joints[i].idx_v();
+            const int32_t startIdx = model.joints[i].idx_v();
             const int32_t endIdx = startIdx + model.joints[i].nv();
 
             // If idx is between start and end, we found the joint we were looking for
@@ -303,9 +303,9 @@ namespace jiminy
             return hresult_t::ERROR_BAD_INPUT;
         }
 
-        pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
-        int32_t jointPositionFirstIdx = model.joints[jointModelIdx].idx_q();
-        int32_t jointNq = model.joints[jointModelIdx].nq();
+        const pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
+        const int32_t jointPositionFirstIdx = model.joints[jointModelIdx].idx_q();
+        const int32_t jointNq = model.joints[jointModelIdx].nq();
         jointPositionIdx.resize(static_cast<std::size_t>(jointNq));
         std::iota(jointPositionIdx.begin(), jointPositionIdx.end(), jointPositionFirstIdx);
 
@@ -425,9 +425,9 @@ namespace jiminy
             return hresult_t::ERROR_BAD_INPUT;
         }
 
-        pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
-        int32_t jointVelocityFirstIdx = model.joints[jointModelIdx].idx_v();
-        int32_t jointNv = model.joints[jointModelIdx].nv();
+        const pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
+        const int32_t jointVelocityFirstIdx = model.joints[jointModelIdx].idx_v();
+        const int32_t jointNv = model.joints[jointModelIdx].nv();
         jointVelocityIdx.resize(static_cast<std::size_t>(jointNv));
         std::iota(jointVelocityIdx.begin(), jointVelocityIdx.end(), jointVelocityFirstIdx);
 
@@ -446,7 +446,7 @@ namespace jiminy
             return hresult_t::ERROR_BAD_INPUT;
         }
 
-        pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
+        const pinocchio::JointIndex jointModelIdx = model.getJointId(jointName);
         jointVelocityFirstIdx = model.joints[jointModelIdx].idx_v();
 
         return hresult_t::SUCCESS;
@@ -694,7 +694,7 @@ namespace jiminy
         // Add new joint to frame list
         pinocchio::FrameIndex childFrameIdx;
         getFrameIdx(modelInOut, childJointNameIn, childFrameIdx);  // Cannot fail at this point
-        pinocchio::FrameIndex newFrameIdx = modelInOut.addJointFrame(
+        const pinocchio::FrameIndex newFrameIdx = modelInOut.addJointFrame(
             newJointIdx, static_cast<int32_t>(modelInOut.frames[childFrameIdx].previousFrame));
 
         // Update child joint previousFrame index
@@ -827,7 +827,7 @@ namespace jiminy
             {
                 continue;
             }
-            pinocchio::JointIndex childJointIdx = modelInOut.frames[childFrameIdx].parent;
+            const pinocchio::JointIndex childJointIdx = modelInOut.frames[childFrameIdx].parent;
 
             // Set child joint to be a child of the new joint
             modelInOut.parents[childJointIdx] = newJointIdx;

python/jiminy_pywrap/include/jiminy/python/utilities.h

@@ -122,7 +122,7 @@ namespace jiminy::python
     {
         if (strncmp(s.basename, "void", 4) == 0)
         {
-            static const char * none = "None";
+            static char constexpr none[] = "None";
             return none;
         }
         const PyTypeObject * py_type = s.pytype_f ? s.pytype_f() : nullptr;
@@ -132,7 +132,7 @@ namespace jiminy::python
         }
         else
         {
-            static const char * object = "object";
+            static char constexpr object[] = "object";
             return object;
         }
     }

python/jiminy_pywrap/src/sensors.cc

@@ -182,7 +182,7 @@ namespace jiminy::python
                 for (const auto & sensorData : sensorsDataType.second)
                 {
                     const std::string & sensorName = sensorData.name;
-                    const std::size_t & sensorIdx = sensorData.idx;
+                    std::size_t sensorIdx = sensorData.idx;
                     const Eigen::Ref<const Eigen::VectorXd> & sensorDataValue = sensorData.value;
                     s << "    (" << sensorIdx << ") " << sensorName << ": "
                       << sensorDataValue.transpose().format(HeavyFmt);
@@ -275,7 +275,7 @@ namespace jiminy::python
             for (std::size_t i = 0; i < fieldnames.size(); ++i)
             {
                 const std::string & field = fieldnames[i];
-                float64_t value = sensorDataValue[i];
+                const float64_t value = sensorDataValue[i];
                 if (i > 0)
                 {
                     s << ", ";