New cpp folder structure

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

libs/transit/transit_version.cpp

@@ -0,0 +1,29 @@
+#include "transit/transit_version.hpp"
+
+#include "base/logging.hpp"
+
+#include <cstdint>
+#include <exception>
+#include <limits>
+
+namespace transit
+{
+TransitVersion GetVersion(Reader & reader)
+{
+  try
+  {
+    NonOwningReaderSource src(reader);
+    uint16_t headerVersion = std::numeric_limits<uint16_t>::max();
+    ReadPrimitiveFromSource(src, headerVersion);
+    CHECK_LESS(headerVersion, static_cast<uint16_t>(TransitVersion::Counter),
+               ("Invalid transit header version."));
+
+    return static_cast<TransitVersion>(headerVersion);
+  }
+  catch (std::exception const & ex)
+  {
+    LOG(LERROR, ("Error reading header version from transit mwm section.", ex.what()));
+    throw;
+  }
+}
+}  // namespace transit