[core] Fix performance-for-range-copy errors

As reported by clang-tidy-8.

5 files changed, 8 insertions, 8 deletions

diff --git a/src/mbgl/renderer/render_orchestrator.cpp b/src/mbgl/renderer/render_orchestrator.cpp
index 9cab1d7caa..b6b16814f0 100644
--- a/src/mbgl/renderer/render_orchestrator.cpp
+++ b/src/mbgl/renderer/render_orchestrator.cpp
@@ -501,7 +501,7 @@ void RenderOrchestrator::queryRenderedSymbols(std::unordered_map<std::string, st
     const Placement& placement = *placementController.getPlacement();
     auto renderedSymbols = placement.getCollisionIndex().queryRenderedSymbols(geometry);
     std::vector<std::reference_wrapper<const RetainedQueryData>> bucketQueryData;
-    for (auto entry : renderedSymbols) {
+    for (const auto& entry : renderedSymbols) {
         bucketQueryData.emplace_back(placement.getQueryData(entry.first));
     }
     // Although symbol query is global, symbol results are only sortable within a bucket
diff --git a/src/mbgl/style/expression/let.cpp b/src/mbgl/style/expression/let.cpp
index 5acd52f578..029c800ef1 100644
--- a/src/mbgl/style/expression/let.cpp
+++ b/src/mbgl/style/expression/let.cpp
@@ -69,7 +69,7 @@ ParseResult Let::parse(const Convertible& value, ParsingContext& ctx) {
 mbgl::Value Let::serialize() const {
     std::vector<mbgl::Value> serialized;
     serialized.emplace_back(getOperator());
-    for (auto entry : bindings) {
+    for (const auto& entry : bindings) {
         serialized.emplace_back(entry.first);
         serialized.emplace_back(entry.second->serialize());
     }
diff --git a/src/mbgl/text/cross_tile_symbol_index.cpp b/src/mbgl/text/cross_tile_symbol_index.cpp
index f806c652e1..76697fb62a 100644
--- a/src/mbgl/text/cross_tile_symbol_index.cpp
+++ b/src/mbgl/text/cross_tile_symbol_index.cpp
@@ -185,7 +185,7 @@ bool CrossTileSymbolLayerIndex::addBucket(const OverscaledTileID& tileID,
 }
 
 void CrossTileSymbolLayerIndex::removeBucketCrossTileIDs(uint8_t zoom, const TileLayerIndex& removedBucket) {
-    for (auto key : removedBucket.indexedSymbolInstances) {
+    for (const auto& key : removedBucket.indexedSymbolInstances) {
         for (auto indexedSymbolInstance : key.second) {
             usedCrossTileIDs[zoom].erase(indexedSymbolInstance.crossTileID);
         }
diff --git a/src/mbgl/tile/geometry_tile.cpp b/src/mbgl/tile/geometry_tile.cpp
index 0271aceb35..92b0a1fa9a 100644
--- a/src/mbgl/tile/geometry_tile.cpp
+++ b/src/mbgl/tile/geometry_tile.cpp
@@ -352,7 +352,7 @@ void GeometryTile::querySourceFeatures(
         return;
     }
 
-    for (auto sourceLayer : *options.sourceLayers) {
+    for (const auto& sourceLayer : *options.sourceLayers) {
         // Go throught all sourceLayers, if any
         // to gather all the features
         auto layer = getData()->getLayer(sourceLayer);
diff --git a/src/mbgl/tile/geometry_tile_data.cpp b/src/mbgl/tile/geometry_tile_data.cpp
index 2f1c9e92fd..d30875ab3b 100644
--- a/src/mbgl/tile/geometry_tile_data.cpp
+++ b/src/mbgl/tile/geometry_tile_data.cpp
@@ -214,7 +214,7 @@ GeometryCollection convertGeometry(const Feature::geometry_type& geometryTileFea
         [&](const MultiLineString<double>& lineStrings) -> GeometryCollection {
             GeometryCollection result;
             result.reserve(lineStrings.size());
-            for (const auto line : lineStrings) {
+            for (const auto& line : lineStrings) {
                 LineString<int16_t> temp;
                 temp.reserve(line.size());
                 for (const auto p : line) {
@@ -227,7 +227,7 @@ GeometryCollection convertGeometry(const Feature::geometry_type& geometryTileFea
         [&](const Polygon<double> polygon) -> GeometryCollection {
             GeometryCollection result;
             result.reserve(polygon.size());
-            for (const auto ring : polygon) {
+            for (const auto& ring : polygon) {
                 LinearRing<int16_t> temp;
                 temp.reserve(ring.size());
                 for (const auto p : ring) {
@@ -240,8 +240,8 @@ GeometryCollection convertGeometry(const Feature::geometry_type& geometryTileFea
         [&](const MultiPolygon<double> polygons) -> GeometryCollection {
             GeometryCollection result;
             result.reserve(polygons.size());
-            for (const auto pg : polygons) {
-                for (const auto r : pg) {
+            for (const auto& pg : polygons) {
+                for (const auto& r : pg) {
                     LinearRing<int16_t> ring;
                     ring.reserve(r.size());
                     for (const auto p : r) {