compilation errors after creating new solver to be added to the CSolverFactory for calaTK

Modif&Errors.cpp

=> MODIFICATIONS

/* In CSolverFactory.h */
+  #include "CSolverStepLengthSelection.h"
+  typedef CSolverStepLengthSelection< TState > SolverStepLengthSelection;
+  enum NumericSolverType {StepLengthSelection, LineSearchUnconstrained, LineSearchConstrained, IpOpt, LBFGS, NLOPT };
-  enum NumericSolverType {LineSearchUnconstrained, LineSearchConstrained, IpOpt, LBFGS, NLOPT };

/* In CSolverFactory.txx */
CSolverFactory< TState >::CreateNewSolver( NumericSolverType solver )
+  case StepLengthSelection:
+    ptrSolver = new SolverStepLengthSelection;
+    break;

CSolverFactory< TState >::GetSolverTypeFromString( std::string sSolver )
+  if ( sSolverLowerCase == "steplengthselection" )
+  {
+    return StepLengthSelection;
+  }

/* In CSolverMultiScale.txx */
CSolverMultiScale< TState >::CSolverMultiScale()
+  : DefaultSingleScaleSolver( "StepLengthSelection" ),


=> COMPILATION ERRORS

CSolverFactory.txx:               In static member function ‘static CALATK::CSolver<TState>* CALATK::CSolverFactory<TState>::CreateNewSolver(CALATK::CSolverFactory<TState>::NumericSolverType) [with TState = CALATK::CStateInitialImageMomentum<float, 1u>]’:
CSolverFactory.txx:85:            instantiated from ‘static CALATK::CSolver<TState>* CALATK::CSolverFactory<TState>::CreateNewSolver(std::string) [with TState = CALATK::CStateInitialImageMomentum<float, 1u>]’
CSolverMultiScale.txx:75:         instantiated from ‘void CALATK::CSolverMultiScale<TState>::SetDefaultSingleScaleSolver() [with TState = CALATK::CStateInitialImageMomentum<float, 1u>]’
CSolverMultiScale.txx:110:        instantiated from ‘bool CALATK::CSolverMultiScale<TState>::Solve() [with TState = CALATK::CStateInitialImageMomentum<float, 1u>]’
json.h:864:                       instantiated from here
CSolverFactory.txx:73:            error: cannot allocate an object of abstract type ‘CALATK::CSolverStepLengthSelection<CALATK::CStateInitialImageMomentum<float, 1u> >’
CSolverStepLengthSelection.h:17:  note:   because the following virtual functions are pure within ‘CALATK::CSolverStepLengthSelection<CALATK::CStateInitialImageMomentum<float, 1u> >’:
CSolver.h:59:                     note: 	bool CALATK::CSolver<TState>::SolvePreInitialized() [with TState = CALATK::CStateInitialImageMomentum<float, 1u>]