Rename to VariableType and Remove duplicate compilations due to templates

Code suggestions by pcarruscag

Co-authored-by: Pedro Gomes <38071223+pcarruscag@users.noreply.github.com>

Author: TobiKattmann

SU2_CFD/include/solvers/CScalarSolver.hpp

@@ -35,7 +35,7 @@
 /*!
  * \class CScalarSolver
  * \brief Main class for defining a scalar solver.
- * \tparam TVariable - Class of C*Variable of the specific solver
+ * \tparam VariableType - Class of variable used by the solver inheriting from this template.
  */
 template <class TVariable>
 class CScalarSolver : public CSolver {
@@ -74,7 +74,7 @@ class CScalarSolver : public CSolver {
   /*!
    * \brief The highest level in the variable hierarchy this solver can safely use.
    */
-  TVariable* nodes = nullptr;
+  VariableType* nodes = nullptr;
 
   /*!
    * \brief Return nodes to allow CSolver::base_nodes to be set.

SU2_CFD/src/solvers/CTransLMSolver.cpp

@@ -25,15 +25,10 @@
  * License along with SU2. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "../../include/solvers/CScalarSolver.inl"
 #include "../../include/solvers/CTransLMSolver.hpp"
 #include "../../include/variables/CTransLMVariable.hpp"
 #include "../../include/variables/CTurbSAVariable.hpp"
 
-/*--- Explicit instantiation of the parent class of CTurbSolver,
- *    to spread the compilation over multiple cpp files. ---*/
-template class CScalarSolver<CTurbVariable>;
-
 /*---  This is the implementation of the Langtry-Menter transition model.
        The main reference for this model is:Langtry, Menter, AIAA J. 47(12) 2009 
        DOI: https://doi.org/10.2514/1.42362 ---*/

SU2_CFD/src/solvers/CTurbSASolver.cpp

@@ -25,15 +25,11 @@
  * License along with SU2. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "../../include/solvers/CScalarSolver.inl"
 #include "../../include/solvers/CTurbSASolver.hpp"
 #include "../../include/variables/CTurbSAVariable.hpp"
 #include "../../../Common/include/parallelization/omp_structure.hpp"
 #include "../../../Common/include/toolboxes/geometry_toolbox.hpp"
 
-/*--- Explicit instantiation of the parent class of CTurbSolver,
- *    to spread the compilation over multiple cpp files. ---*/
-template class CScalarSolver<CTurbVariable>;
 
 CTurbSASolver::CTurbSASolver(void) : CTurbSolver(false) { }
 

SU2_CFD/src/solvers/CTurbSSTSolver.cpp

@@ -25,15 +25,11 @@
  * License along with SU2. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "../../include/solvers/CScalarSolver.inl"
 #include "../../include/solvers/CTurbSSTSolver.hpp"
 #include "../../include/variables/CTurbSSTVariable.hpp"
 #include "../../../Common/include/parallelization/omp_structure.hpp"
 #include "../../../Common/include/toolboxes/geometry_toolbox.hpp"
 
-/*--- Explicit instantiation of the parent class of CTurbSolver,
- *    to spread the compilation over multiple cpp files. ---*/
-template class CScalarSolver<CTurbVariable>;
 
 CTurbSSTSolver::CTurbSSTSolver(void) : CTurbSolver(true) { }
 

SU2_CFD/src/solvers/CTurbSolver.cpp

@@ -28,7 +28,10 @@
 #include "../../include/solvers/CTurbSolver.hpp"
 #include "../../../Common/include/parallelization/omp_structure.hpp"
 #include "../../../Common/include/toolboxes/geometry_toolbox.hpp"
+#include "../../include/solvers/CScalarSolver.inl"
 
+/*--- Explicit instantiation of the parent class of CTurbSolver. ---*/
+template class CScalarSolver<CTurbVariable>;
 
 CTurbSolver::CTurbSolver(bool conservative) : CScalarSolver<CTurbVariable>(conservative) { }