[search] Add FeatureTypeToString().

indexer/indexer.pro

@@ -38,6 +38,7 @@ SOURCES += \
     mwm_set.cpp \
     index.cpp \
     categories_holder.cpp \
+    search_string_utils.cpp
 
 HEADERS += \
     feature.hpp \

indexer/search_string_utils.cpp

@@ -0,0 +1,7 @@
+#include "search_string_utils.hpp"
+
+strings::UniString search::FeatureTypeToString(uint32_t type)
+{
+  string s = "!type:" + strings::to_string(type);
+  return strings::UniString(s.begin(), s.end());
+}

indexer/search_string_utils.hpp

@@ -21,4 +21,6 @@ void SplitUniString(strings::UniString const & uniS, F f, DelimsT const & delims
     f(iter.GetUniString());
 }
 
+strings::UniString FeatureTypeToString(uint32_t type);
+
 }  // namespace search