Add a templated flatten function

Makefile.am

@@ -17,6 +17,7 @@ pcb2gcode_SOURCES = \
     drill.cpp \
     eulerian_paths.hpp \
     eulerian_paths.cpp \
+    flatten.hpp \
     geometry.hpp \
     geometry_int.hpp \
     gerberimporter.hpp \

flatten.hpp

@@ -0,0 +1,16 @@
+#ifndef FLATTEN_HPP
+#define FLATTEN_HPP
+
+template <typename T>
+std::vector<T> flatten(const std::vector<std::vector<T>>& v) {
+  std::size_t total_size = 0;
+  for (const auto& sub : v)
+    total_size += sub.size(); // I wish there was a transform_accumulate
+  std::vector<T> result;
+  result.reserve(total_size);
+  for (const auto& sub : v)
+    result.insert(result.end(), sub.begin(), sub.end());
+  return result;
+}
+
+#endif // FLATTEN_HPP

surface_vectorial.cpp

@@ -50,6 +50,7 @@ using std::map;
 using boost::optional;
 using boost::make_optional;
 
+#include "flatten.hpp"
 #include "tsp_solver.hpp"
 #include "surface_vectorial.hpp"
 #include "segmentize.hpp"
@@ -178,14 +179,6 @@ vector<polygon_type_fp> find_thermal_reliefs(const multi_polygon_type_fp& millin
   return holes;
 }
 
-vector<pair<linestring_type_fp, bool>> flatten_mls(const vector<vector<pair<linestring_type_fp, bool>>>& v) {
-  vector<pair<linestring_type_fp, bool>> result;
-  for (const auto& sub : v) {
-    result.insert(result.end(), sub.begin(), sub.end());
-  }
-  return result;
-}
-
 void Surface_vectorial::write_svgs(const string& tool_suffix, coordinate_type_fp tool_diameter,
                                    const vector<vector<pair<linestring_type_fp, bool>>>& new_trace_toolpaths,
                                    coordinate_type_fp tolerance, bool find_contentions) const {
@@ -833,7 +826,7 @@ vector<pair<coordinate_type_fp, vector<shared_ptr<icoords>>>> Surface_vectorial:
       }
       const string tool_suffix = tool_count > 1 ? "_" + std::to_string(tool_index) : "";
       write_svgs(tool_suffix, tool_diameter, new_trace_toolpaths, mill->tolerance, tool_index == tool_count - 1);
-      auto new_toolpath = flatten_mls(new_trace_toolpaths);
+      auto new_toolpath = flatten(new_trace_toolpaths);
       multi_linestring_type_fp combined_toolpath = post_process_toolpath(isolator, new_toolpath);
       results[tool_index] = make_pair(tool_diameter, mls_to_icoords(mirror_toolpath(combined_toolpath, mirror)));
     }
@@ -868,7 +861,7 @@ vector<pair<coordinate_type_fp, vector<shared_ptr<icoords>>>> Surface_vectorial:
       new_trace_toolpaths[trace_index] = new_trace_toolpath;
     }
     write_svgs("", cutter->tool_diameter, new_trace_toolpaths, mill->tolerance, false);
-    auto new_toolpath = flatten_mls(new_trace_toolpaths);
+    auto new_toolpath = flatten(new_trace_toolpaths);
     multi_linestring_type_fp combined_toolpath = post_process_toolpath(cutter, new_toolpath);
     return {make_pair(cutter->tool_diameter, mls_to_icoords(mirror_toolpath(combined_toolpath, mirror)))};
   }