New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/indexer/drules_selector.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "indexer/feature.hpp"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace drule
+{
+
+// Runtime feature style selector absract interface.
+class ISelector
+{
+public:
+  virtual ~ISelector() = default;
+
+  // If ISelector.Test returns true then style is applicable for the feature,
+  // otherwise, if ISelector.Test returns false, style cannot be applied to the feature.
+  virtual bool Test(FeatureType & ft, int zoom) const = 0;
+};
+
+// Factory method which builds ISelector from a string.
+std::unique_ptr<ISelector> ParseSelector(std::string const & str);
+
+// Factory method which builds composite ISelector from a set of string.
+std::unique_ptr<ISelector> ParseSelector(std::vector<std::string> const & strs);
+
+}  // namespace drule