Now build SimpleITK into static libs and use (auto)cxx.

cxx/ffi_extra.cxx

@@ -0,0 +1,58 @@
+#include "ffi_extra.h"
+
+#include <map>
+#include <memory>
+#include <utility>
+#include <vector>
+#include <string>
+
+
+std::unique_ptr<ParameterMap> get_transform_parameter_map(itk::simple::ElastixImageFilter& tfilter, const unsigned int index) {
+    itk::simple::ElastixImageFilter::ParameterMapType parameter_map = tfilter.GetTransformParameterMap(index);
+    ParameterMap transform_parameter_map = ParameterMap(parameter_map);
+    auto ptr = std::make_unique<ParameterMap>(parameter_map);
+    return ptr;
+}
+
+std::unique_ptr<ParameterMap> get_default_parameter_map(const std::string& kind) {
+    itk::simple::ElastixImageFilter::ParameterMapType parameter_map = itk::simple::GetDefaultParameterMap(kind);
+    ParameterMap default_parameter_map = ParameterMap(parameter_map);
+    auto ptr = std::make_unique<ParameterMap>(default_parameter_map);
+    return ptr;
+}
+
+void set_parameter_map(itk::simple::ElastixImageFilter& tfilter, const std::unique_ptr<ParameterMap>& parameter_map) {
+    tfilter.SetParameterMap(parameter_map->parameters);
+};
+
+ParameterMap::ParameterMap() = default;
+ParameterMap::~ParameterMap() = default;
+
+ParameterMap::ParameterMap(itk::simple::ElastixImageFilter::ParameterMapType parameter_map) {
+    this->parameters = std::move(parameter_map);
+}
+
+std::unique_ptr<ParameterMap> new_parameter_map() {
+    ParameterMap parameter_map;
+    auto ptr = std::make_unique<ParameterMap>(parameter_map);
+    return ptr;
+}
+
+void ParameterMap::insert(const std::string &key, const std::vector<std::string> &value) {
+    this->parameters.emplace(key, value);
+}
+
+std::unique_ptr<std::vector<std::string>> ParameterMap::keys() const {
+    std::vector<std::string> keys;
+    for (auto &[key, value] : this->parameters) {
+        keys.push_back(key);
+    }
+    auto ptr = std::make_unique<std::vector<std::string>>(keys);
+    return ptr;
+}
+
+std::unique_ptr<std::vector<std::string>> ParameterMap::get(const std::string& key) const {
+    std::vector<std::string> value = this->parameters.at(key);
+    auto ptr = std::make_unique<std::vector<std::string>>(value);
+    return ptr;
+}