[core] Encapsulate placement code handling symbols sort ranges

2 files changed, 3 insertions, 8 deletions

diff --git a/src/mbgl/layout/symbol_instance.hpp b/src/mbgl/layout/symbol_instance.hpp
index 3303e5f7e3..fa05affc13 100644
--- a/src/mbgl/layout/symbol_instance.hpp
+++ b/src/mbgl/layout/symbol_instance.hpp
@@ -123,11 +123,6 @@ public:
     static constexpr uint32_t invalidCrossTileID() { return std::numeric_limits<uint32_t>::max(); }
 };
 
-class SortKeyRange {
-public:
-    float sortKey;
-    size_t symbolInstanceStart;
-    size_t symbolInstanceEnd;
-};
+using SymbolInstanceReferences = std::vector<std::reference_wrapper<const SymbolInstance>>;
 
 } // namespace mbgl
diff --git a/src/mbgl/layout/symbol_layout.cpp b/src/mbgl/layout/symbol_layout.cpp
index 63ce223574..093b11de1d 100644
--- a/src/mbgl/layout/symbol_layout.cpp
+++ b/src/mbgl/layout/symbol_layout.cpp
@@ -613,8 +613,8 @@ void SymbolLayout::addFeature(const std::size_t layoutFeatureIndex,
                                          iconType);
 
             if (sortFeaturesByKey) {
-                if (sortKeyRanges.size() && sortKeyRanges.back().sortKey == feature.sortKey) {
-                    sortKeyRanges.back().symbolInstanceEnd = symbolInstances.size();
+                if (!sortKeyRanges.empty() && sortKeyRanges.back().sortKey == feature.sortKey) {
+                    sortKeyRanges.back().end = symbolInstances.size();
                 } else {
                     sortKeyRanges.push_back({feature.sortKey, symbolInstances.size() - 1, symbolInstances.size()});
                 }