Construct an adjacency list in order to discover turns.

Author: danpat

include/util/vector_tile.hpp

@@ -28,6 +28,7 @@ const constexpr std::uint32_t VARIANT_TYPE_SINT64 = 6;
 const constexpr std::uint32_t VARIANT_TYPE_BOOL = 7;
 const constexpr std::uint32_t VARIANT_TYPE_STRING = 1;
 const constexpr std::uint32_t VARIANT_TYPE_DOUBLE = 3;
+const constexpr std::uint32_t VARIANT_TYPE_FLOAT = 2;
 
 // Vector tiles are 4096 virtual pixels on each side
 const constexpr double EXTENT = 4096.0;