Remove unnecessary and only use of boost::optional

Author: joto

src/options.hpp

@@ -12,7 +12,6 @@
 
 #include <osmium/osm/box.hpp>
 
-#include <boost/optional.hpp>
 #include <memory>
 #include <string>
 #include <vector>
@@ -135,7 +134,7 @@ class options_t
     /// Name of the flat node file used. Empty if flat node file is not enabled.
     std::string flat_node_file{};
 
-    boost::optional<std::string> tag_transform_script{boost::none};
+    std::string tag_transform_script;
 
     bool create = false;
     bool pass_prompt = false;

src/tagtransform-lua.cpp

@@ -21,7 +21,7 @@ lua_tagtransform_t::lua_tagtransform_t(options_t const *options)
 : m_node_func("filter_tags_node"), m_way_func("filter_tags_way"),
   m_rel_func("filter_basic_tags_rel"),
   m_rel_mem_func("filter_tags_relation_member"),
-  m_lua_file(options->tag_transform_script.get()),
+  m_lua_file(options->tag_transform_script),
   m_extra_attributes(options->extra_attributes)
 {
     open_style();

src/tagtransform.cpp

@@ -7,11 +7,11 @@
  * For a full list of authors see the git log.
  */
 
-#include "tagtransform.hpp"
 #include "config.h"
 #include "logging.hpp"
 #include "options.hpp"
 #include "tagtransform-c.hpp"
+#include "tagtransform.hpp"
 
 #ifdef HAVE_LUA
 #include "tagtransform-lua.hpp"
@@ -21,10 +21,10 @@ std::unique_ptr<tagtransform_t>
 tagtransform_t::make_tagtransform(options_t const *options,
                                   export_list const &exlist)
 {
-    if (options->tag_transform_script) {
+    if (!options->tag_transform_script.empty()) {
 #ifdef HAVE_LUA
         log_debug("Using lua based tag transformations with script {}",
-                  options->tag_transform_script.get());
+                  options->tag_transform_script);
         return std::unique_ptr<tagtransform_t>(new lua_tagtransform_t{options});
 #else
         throw std::runtime_error{"Error: Could not init lua tag transform, as "