ENH: Wrap new variant of itkLBFGS2Optimizerv4

The new optimizer is based on modern c++ code rather than converted
fortran code.  The new optimizer also has a few interesting modes
that are not available in the original fortran implementation.

The LBFGS2 optimizer is only wrappable for double precision
internal computation type due to current limitations of the
core library only being able to be compiled for one data
type at a time.

Add static_assert to more clearly present this limitation
at compiletime.

Modules/Numerics/Optimizersv4/include/itkLBFGS2Optimizerv4.h

@@ -183,7 +183,8 @@ class ITK_TEMPLATE_EXPORT LBFGS2Optimizerv4Template
    * define so lbfgs.h uses the correct version
    **/
   using PrecisionType = double;
-
+  static_assert(std::is_same<TInternalComputationValueType, double>::value,
+                "LBFGS2Optimizerv4Template only supports double precision");
   /** Standard "Self" type alias. */
   using Self = LBFGS2Optimizerv4Template;
   using Superclass = GradientDescentOptimizerv4Template<TInternalComputationValueType>;
@@ -518,20 +519,19 @@ class ITK_TEMPLATE_EXPORT LBFGS2Optimizerv4Template
   /**
    * itkGradientDecentOptimizerv4Template specific non supported methods.
    */
-  void
-  SetMinimumConvergenceValue(double) override
+  void SetMinimumConvergenceValue(PrecisionType) override
   {
     itkWarningMacro("Not supported. Please use LBFGS specific convergence methods.");
   };
   void SetConvergenceWindowSize(SizeValueType) override
   {
     itkWarningMacro("Not supported. Please use LBFGS specific convergence methods.");
   };
-  const double &
+  const PrecisionType &
   GetConvergenceValue() const override
   {
     itkWarningMacro("Not supported. Please use LBFGS specific convergence methods.");
-    static double value = 0;
+    static PrecisionType value{};
     return value;
   };
 

Modules/Numerics/Optimizersv4/src/itkLBFGS2Optimizerv4.cxx

@@ -27,15 +27,11 @@ operator<<(std::ostream & out, const LBFGS2Optimizerv4Enums::LineSearchMethod va
     switch (value)
     {
       case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_DEFAULT:
-        return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_DEFAULT";
-        //                case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_MORETHUENTE:
-        //                    return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_MORETHUENTE";
+        return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_DEFAULT (LINESEARCH_MORETHUENTE)";
       case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_ARMIJO:
         return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_ARMIJO";
       case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING:
-        return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING";
-        //                case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_WOLFE:
-        //                    return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_WOLFE";
+        return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING (LINESEARCH_BACKTRACKING_WOLFE)";
       case LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_STRONG_WOLFE:
         return "itk::LBFGS2Optimizerv4Enums::LineSearchMethod::LINESEARCH_BACKTRACKING_STRONG_WOLFE";
       default:

Modules/Numerics/Optimizersv4/wrapping/itkLBFGS2Optimizerv4.wrap

@@ -0,0 +1,13 @@
+set(WRAPPER_AUTO_INCLUDE_HEADERS OFF)
+itk_wrap_include("itkLBFGS2Optimizerv4.h")
+
+itk_wrap_simple_class("itk::LBFGS2Optimizerv4Enums")
+
+# only double supported at the momemnt unique(types "D;${WRAP_ITK_REAL}")
+unique(types "D")
+
+itk_wrap_class("itk::LBFGS2Optimizerv4Template" POINTER_WITH_CONST_POINTER)
+foreach(t ${types})
+  itk_wrap_template("${ITKM_${t}}" "${ITKT_${t}}")
+endforeach()
+itk_end_wrap_class()