[core] clang-tidy fixes

10 files changed, 236 insertions, 236 deletions

diff --git a/include/mbgl/style/layers/background_layer.hpp b/include/mbgl/style/layers/background_layer.hpp
index f0efa7acba..1e1f4b78a8 100644
--- a/include/mbgl/style/layers/background_layer.hpp
+++ b/include/mbgl/style/layers/background_layer.hpp
@@ -25,20 +25,20 @@ public:
     // Paint properties
 
     static PropertyValue<Color> getDefaultBackgroundColor();
-    PropertyValue<Color> getBackgroundColor() const;
-    void setBackgroundColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getBackgroundColor() const;
+    void setBackgroundColor(const PropertyValue<Color>&);
     void setBackgroundColorTransition(const TransitionOptions&);
     TransitionOptions getBackgroundColorTransition() const;
 
     static PropertyValue<std::string> getDefaultBackgroundPattern();
-    PropertyValue<std::string> getBackgroundPattern() const;
-    void setBackgroundPattern(PropertyValue<std::string>);
+    const PropertyValue<std::string>& getBackgroundPattern() const;
+    void setBackgroundPattern(const PropertyValue<std::string>&);
     void setBackgroundPatternTransition(const TransitionOptions&);
     TransitionOptions getBackgroundPatternTransition() const;
 
     static PropertyValue<float> getDefaultBackgroundOpacity();
-    PropertyValue<float> getBackgroundOpacity() const;
-    void setBackgroundOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getBackgroundOpacity() const;
+    void setBackgroundOpacity(const PropertyValue<float>&);
     void setBackgroundOpacityTransition(const TransitionOptions&);
     TransitionOptions getBackgroundOpacityTransition() const;
 
diff --git a/include/mbgl/style/layers/circle_layer.hpp b/include/mbgl/style/layers/circle_layer.hpp
index 08ec686ff2..4095bc8fe7 100644
--- a/include/mbgl/style/layers/circle_layer.hpp
+++ b/include/mbgl/style/layers/circle_layer.hpp
@@ -25,68 +25,68 @@ public:
     // Paint properties
 
     static PropertyValue<float> getDefaultCircleRadius();
-    PropertyValue<float> getCircleRadius() const;
-    void setCircleRadius(PropertyValue<float>);
+    const PropertyValue<float>& getCircleRadius() const;
+    void setCircleRadius(const PropertyValue<float>&);
     void setCircleRadiusTransition(const TransitionOptions&);
     TransitionOptions getCircleRadiusTransition() const;
 
     static PropertyValue<Color> getDefaultCircleColor();
-    PropertyValue<Color> getCircleColor() const;
-    void setCircleColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getCircleColor() const;
+    void setCircleColor(const PropertyValue<Color>&);
     void setCircleColorTransition(const TransitionOptions&);
     TransitionOptions getCircleColorTransition() const;
 
     static PropertyValue<float> getDefaultCircleBlur();
-    PropertyValue<float> getCircleBlur() const;
-    void setCircleBlur(PropertyValue<float>);
+    const PropertyValue<float>& getCircleBlur() const;
+    void setCircleBlur(const PropertyValue<float>&);
     void setCircleBlurTransition(const TransitionOptions&);
     TransitionOptions getCircleBlurTransition() const;
 
     static PropertyValue<float> getDefaultCircleOpacity();
-    PropertyValue<float> getCircleOpacity() const;
-    void setCircleOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getCircleOpacity() const;
+    void setCircleOpacity(const PropertyValue<float>&);
     void setCircleOpacityTransition(const TransitionOptions&);
     TransitionOptions getCircleOpacityTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultCircleTranslate();
-    PropertyValue<std::array<float, 2>> getCircleTranslate() const;
-    void setCircleTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getCircleTranslate() const;
+    void setCircleTranslate(const PropertyValue<std::array<float, 2>>&);
     void setCircleTranslateTransition(const TransitionOptions&);
     TransitionOptions getCircleTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultCircleTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getCircleTranslateAnchor() const;
-    void setCircleTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getCircleTranslateAnchor() const;
+    void setCircleTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setCircleTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getCircleTranslateAnchorTransition() const;
 
     static PropertyValue<CirclePitchScaleType> getDefaultCirclePitchScale();
-    PropertyValue<CirclePitchScaleType> getCirclePitchScale() const;
-    void setCirclePitchScale(PropertyValue<CirclePitchScaleType>);
+    const PropertyValue<CirclePitchScaleType>& getCirclePitchScale() const;
+    void setCirclePitchScale(const PropertyValue<CirclePitchScaleType>&);
     void setCirclePitchScaleTransition(const TransitionOptions&);
     TransitionOptions getCirclePitchScaleTransition() const;
 
     static PropertyValue<AlignmentType> getDefaultCirclePitchAlignment();
-    PropertyValue<AlignmentType> getCirclePitchAlignment() const;
-    void setCirclePitchAlignment(PropertyValue<AlignmentType>);
+    const PropertyValue<AlignmentType>& getCirclePitchAlignment() const;
+    void setCirclePitchAlignment(const PropertyValue<AlignmentType>&);
     void setCirclePitchAlignmentTransition(const TransitionOptions&);
     TransitionOptions getCirclePitchAlignmentTransition() const;
 
     static PropertyValue<float> getDefaultCircleStrokeWidth();
-    PropertyValue<float> getCircleStrokeWidth() const;
-    void setCircleStrokeWidth(PropertyValue<float>);
+    const PropertyValue<float>& getCircleStrokeWidth() const;
+    void setCircleStrokeWidth(const PropertyValue<float>&);
     void setCircleStrokeWidthTransition(const TransitionOptions&);
     TransitionOptions getCircleStrokeWidthTransition() const;
 
     static PropertyValue<Color> getDefaultCircleStrokeColor();
-    PropertyValue<Color> getCircleStrokeColor() const;
-    void setCircleStrokeColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getCircleStrokeColor() const;
+    void setCircleStrokeColor(const PropertyValue<Color>&);
     void setCircleStrokeColorTransition(const TransitionOptions&);
     TransitionOptions getCircleStrokeColorTransition() const;
 
     static PropertyValue<float> getDefaultCircleStrokeOpacity();
-    PropertyValue<float> getCircleStrokeOpacity() const;
-    void setCircleStrokeOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getCircleStrokeOpacity() const;
+    void setCircleStrokeOpacity(const PropertyValue<float>&);
     void setCircleStrokeOpacityTransition(const TransitionOptions&);
     TransitionOptions getCircleStrokeOpacityTransition() const;
 
diff --git a/include/mbgl/style/layers/fill_extrusion_layer.hpp b/include/mbgl/style/layers/fill_extrusion_layer.hpp
index c4b7ecfcdb..80152de80a 100644
--- a/include/mbgl/style/layers/fill_extrusion_layer.hpp
+++ b/include/mbgl/style/layers/fill_extrusion_layer.hpp
@@ -25,50 +25,50 @@ public:
     // Paint properties
 
     static PropertyValue<float> getDefaultFillExtrusionOpacity();
-    PropertyValue<float> getFillExtrusionOpacity() const;
-    void setFillExtrusionOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getFillExtrusionOpacity() const;
+    void setFillExtrusionOpacity(const PropertyValue<float>&);
     void setFillExtrusionOpacityTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionOpacityTransition() const;
 
     static PropertyValue<Color> getDefaultFillExtrusionColor();
-    PropertyValue<Color> getFillExtrusionColor() const;
-    void setFillExtrusionColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getFillExtrusionColor() const;
+    void setFillExtrusionColor(const PropertyValue<Color>&);
     void setFillExtrusionColorTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionColorTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultFillExtrusionTranslate();
-    PropertyValue<std::array<float, 2>> getFillExtrusionTranslate() const;
-    void setFillExtrusionTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getFillExtrusionTranslate() const;
+    void setFillExtrusionTranslate(const PropertyValue<std::array<float, 2>>&);
     void setFillExtrusionTranslateTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultFillExtrusionTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getFillExtrusionTranslateAnchor() const;
-    void setFillExtrusionTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getFillExtrusionTranslateAnchor() const;
+    void setFillExtrusionTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setFillExtrusionTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionTranslateAnchorTransition() const;
 
     static PropertyValue<std::string> getDefaultFillExtrusionPattern();
-    PropertyValue<std::string> getFillExtrusionPattern() const;
-    void setFillExtrusionPattern(PropertyValue<std::string>);
+    const PropertyValue<std::string>& getFillExtrusionPattern() const;
+    void setFillExtrusionPattern(const PropertyValue<std::string>&);
     void setFillExtrusionPatternTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionPatternTransition() const;
 
     static PropertyValue<float> getDefaultFillExtrusionHeight();
-    PropertyValue<float> getFillExtrusionHeight() const;
-    void setFillExtrusionHeight(PropertyValue<float>);
+    const PropertyValue<float>& getFillExtrusionHeight() const;
+    void setFillExtrusionHeight(const PropertyValue<float>&);
     void setFillExtrusionHeightTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionHeightTransition() const;
 
     static PropertyValue<float> getDefaultFillExtrusionBase();
-    PropertyValue<float> getFillExtrusionBase() const;
-    void setFillExtrusionBase(PropertyValue<float>);
+    const PropertyValue<float>& getFillExtrusionBase() const;
+    void setFillExtrusionBase(const PropertyValue<float>&);
     void setFillExtrusionBaseTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionBaseTransition() const;
 
     static PropertyValue<bool> getDefaultFillExtrusionVerticalGradient();
-    PropertyValue<bool> getFillExtrusionVerticalGradient() const;
-    void setFillExtrusionVerticalGradient(PropertyValue<bool>);
+    const PropertyValue<bool>& getFillExtrusionVerticalGradient() const;
+    void setFillExtrusionVerticalGradient(const PropertyValue<bool>&);
     void setFillExtrusionVerticalGradientTransition(const TransitionOptions&);
     TransitionOptions getFillExtrusionVerticalGradientTransition() const;
 
diff --git a/include/mbgl/style/layers/fill_layer.hpp b/include/mbgl/style/layers/fill_layer.hpp
index 6a402f28f7..e4872a5fd8 100644
--- a/include/mbgl/style/layers/fill_layer.hpp
+++ b/include/mbgl/style/layers/fill_layer.hpp
@@ -25,44 +25,44 @@ public:
     // Paint properties
 
     static PropertyValue<bool> getDefaultFillAntialias();
-    PropertyValue<bool> getFillAntialias() const;
-    void setFillAntialias(PropertyValue<bool>);
+    const PropertyValue<bool>& getFillAntialias() const;
+    void setFillAntialias(const PropertyValue<bool>&);
     void setFillAntialiasTransition(const TransitionOptions&);
     TransitionOptions getFillAntialiasTransition() const;
 
     static PropertyValue<float> getDefaultFillOpacity();
-    PropertyValue<float> getFillOpacity() const;
-    void setFillOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getFillOpacity() const;
+    void setFillOpacity(const PropertyValue<float>&);
     void setFillOpacityTransition(const TransitionOptions&);
     TransitionOptions getFillOpacityTransition() const;
 
     static PropertyValue<Color> getDefaultFillColor();
-    PropertyValue<Color> getFillColor() const;
-    void setFillColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getFillColor() const;
+    void setFillColor(const PropertyValue<Color>&);
     void setFillColorTransition(const TransitionOptions&);
     TransitionOptions getFillColorTransition() const;
 
     static PropertyValue<Color> getDefaultFillOutlineColor();
-    PropertyValue<Color> getFillOutlineColor() const;
-    void setFillOutlineColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getFillOutlineColor() const;
+    void setFillOutlineColor(const PropertyValue<Color>&);
     void setFillOutlineColorTransition(const TransitionOptions&);
     TransitionOptions getFillOutlineColorTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultFillTranslate();
-    PropertyValue<std::array<float, 2>> getFillTranslate() const;
-    void setFillTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getFillTranslate() const;
+    void setFillTranslate(const PropertyValue<std::array<float, 2>>&);
     void setFillTranslateTransition(const TransitionOptions&);
     TransitionOptions getFillTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultFillTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getFillTranslateAnchor() const;
-    void setFillTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getFillTranslateAnchor() const;
+    void setFillTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setFillTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getFillTranslateAnchorTransition() const;
 
     static PropertyValue<std::string> getDefaultFillPattern();
-    PropertyValue<std::string> getFillPattern() const;
-    void setFillPattern(PropertyValue<std::string>);
+    const PropertyValue<std::string>& getFillPattern() const;
+    void setFillPattern(const PropertyValue<std::string>&);
     void setFillPatternTransition(const TransitionOptions&);
     TransitionOptions getFillPatternTransition() const;
 
diff --git a/include/mbgl/style/layers/heatmap_layer.hpp b/include/mbgl/style/layers/heatmap_layer.hpp
index 4c3ae0daf8..bbd9d6eb7b 100644
--- a/include/mbgl/style/layers/heatmap_layer.hpp
+++ b/include/mbgl/style/layers/heatmap_layer.hpp
@@ -26,32 +26,32 @@ public:
     // Paint properties
 
     static PropertyValue<float> getDefaultHeatmapRadius();
-    PropertyValue<float> getHeatmapRadius() const;
-    void setHeatmapRadius(PropertyValue<float>);
+    const PropertyValue<float>& getHeatmapRadius() const;
+    void setHeatmapRadius(const PropertyValue<float>&);
     void setHeatmapRadiusTransition(const TransitionOptions&);
     TransitionOptions getHeatmapRadiusTransition() const;
 
     static PropertyValue<float> getDefaultHeatmapWeight();
-    PropertyValue<float> getHeatmapWeight() const;
-    void setHeatmapWeight(PropertyValue<float>);
+    const PropertyValue<float>& getHeatmapWeight() const;
+    void setHeatmapWeight(const PropertyValue<float>&);
     void setHeatmapWeightTransition(const TransitionOptions&);
     TransitionOptions getHeatmapWeightTransition() const;
 
     static PropertyValue<float> getDefaultHeatmapIntensity();
-    PropertyValue<float> getHeatmapIntensity() const;
-    void setHeatmapIntensity(PropertyValue<float>);
+    const PropertyValue<float>& getHeatmapIntensity() const;
+    void setHeatmapIntensity(const PropertyValue<float>&);
     void setHeatmapIntensityTransition(const TransitionOptions&);
     TransitionOptions getHeatmapIntensityTransition() const;
 
     static ColorRampPropertyValue getDefaultHeatmapColor();
-    ColorRampPropertyValue getHeatmapColor() const;
-    void setHeatmapColor(ColorRampPropertyValue);
+    const ColorRampPropertyValue& getHeatmapColor() const;
+    void setHeatmapColor(const ColorRampPropertyValue&);
     void setHeatmapColorTransition(const TransitionOptions&);
     TransitionOptions getHeatmapColorTransition() const;
 
     static PropertyValue<float> getDefaultHeatmapOpacity();
-    PropertyValue<float> getHeatmapOpacity() const;
-    void setHeatmapOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getHeatmapOpacity() const;
+    void setHeatmapOpacity(const PropertyValue<float>&);
     void setHeatmapOpacityTransition(const TransitionOptions&);
     TransitionOptions getHeatmapOpacityTransition() const;
 
diff --git a/include/mbgl/style/layers/hillshade_layer.hpp b/include/mbgl/style/layers/hillshade_layer.hpp
index 760e70aa75..d2eebadf9d 100644
--- a/include/mbgl/style/layers/hillshade_layer.hpp
+++ b/include/mbgl/style/layers/hillshade_layer.hpp
@@ -25,38 +25,38 @@ public:
     // Paint properties
 
     static PropertyValue<float> getDefaultHillshadeIlluminationDirection();
-    PropertyValue<float> getHillshadeIlluminationDirection() const;
-    void setHillshadeIlluminationDirection(PropertyValue<float>);
+    const PropertyValue<float>& getHillshadeIlluminationDirection() const;
+    void setHillshadeIlluminationDirection(const PropertyValue<float>&);
     void setHillshadeIlluminationDirectionTransition(const TransitionOptions&);
     TransitionOptions getHillshadeIlluminationDirectionTransition() const;
 
     static PropertyValue<HillshadeIlluminationAnchorType> getDefaultHillshadeIlluminationAnchor();
-    PropertyValue<HillshadeIlluminationAnchorType> getHillshadeIlluminationAnchor() const;
-    void setHillshadeIlluminationAnchor(PropertyValue<HillshadeIlluminationAnchorType>);
+    const PropertyValue<HillshadeIlluminationAnchorType>& getHillshadeIlluminationAnchor() const;
+    void setHillshadeIlluminationAnchor(const PropertyValue<HillshadeIlluminationAnchorType>&);
     void setHillshadeIlluminationAnchorTransition(const TransitionOptions&);
     TransitionOptions getHillshadeIlluminationAnchorTransition() const;
 
     static PropertyValue<float> getDefaultHillshadeExaggeration();
-    PropertyValue<float> getHillshadeExaggeration() const;
-    void setHillshadeExaggeration(PropertyValue<float>);
+    const PropertyValue<float>& getHillshadeExaggeration() const;
+    void setHillshadeExaggeration(const PropertyValue<float>&);
     void setHillshadeExaggerationTransition(const TransitionOptions&);
     TransitionOptions getHillshadeExaggerationTransition() const;
 
     static PropertyValue<Color> getDefaultHillshadeShadowColor();
-    PropertyValue<Color> getHillshadeShadowColor() const;
-    void setHillshadeShadowColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getHillshadeShadowColor() const;
+    void setHillshadeShadowColor(const PropertyValue<Color>&);
     void setHillshadeShadowColorTransition(const TransitionOptions&);
     TransitionOptions getHillshadeShadowColorTransition() const;
 
     static PropertyValue<Color> getDefaultHillshadeHighlightColor();
-    PropertyValue<Color> getHillshadeHighlightColor() const;
-    void setHillshadeHighlightColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getHillshadeHighlightColor() const;
+    void setHillshadeHighlightColor(const PropertyValue<Color>&);
     void setHillshadeHighlightColorTransition(const TransitionOptions&);
     TransitionOptions getHillshadeHighlightColorTransition() const;
 
     static PropertyValue<Color> getDefaultHillshadeAccentColor();
-    PropertyValue<Color> getHillshadeAccentColor() const;
-    void setHillshadeAccentColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getHillshadeAccentColor() const;
+    void setHillshadeAccentColor(const PropertyValue<Color>&);
     void setHillshadeAccentColorTransition(const TransitionOptions&);
     TransitionOptions getHillshadeAccentColorTransition() const;
 
diff --git a/include/mbgl/style/layers/layer.hpp.ejs b/include/mbgl/style/layers/layer.hpp.ejs
index a7a8ff35c5..8371f11910 100644
--- a/include/mbgl/style/layers/layer.hpp.ejs
+++ b/include/mbgl/style/layers/layer.hpp.ejs
@@ -43,8 +43,8 @@ public:
 
 <% for (const property of layoutProperties) { -%>
     static <%- propertyValueType(property) %> getDefault<%- camelize(property.name) %>();
-    <%- propertyValueType(property) %> get<%- camelize(property.name) %>() const;
-    void set<%- camelize(property.name) %>(<%- propertyValueType(property) %>);
+    const <%- propertyValueType(property) %>& get<%- camelize(property.name) %>() const;
+    void set<%- camelize(property.name) %>(const <%- propertyValueType(property) %>&);
 
 <% } -%>
 <% } -%>
@@ -52,8 +52,8 @@ public:
 
 <% for (const property of paintProperties) { -%>
     static <%- propertyValueType(property) %> getDefault<%- camelize(property.name) %>();
-    <%- propertyValueType(property) %> get<%- camelize(property.name) %>() const;
-    void set<%- camelize(property.name) %>(<%- propertyValueType(property) %>);
+    const <%- propertyValueType(property) %>& get<%- camelize(property.name) %>() const;
+    void set<%- camelize(property.name) %>(const <%- propertyValueType(property) %>&);
     void set<%- camelize(property.name) %>Transition(const TransitionOptions&);
     TransitionOptions get<%- camelize(property.name) %>Transition() const;
 
diff --git a/include/mbgl/style/layers/line_layer.hpp b/include/mbgl/style/layers/line_layer.hpp
index 5993ac8730..21fdb3653e 100644
--- a/include/mbgl/style/layers/line_layer.hpp
+++ b/include/mbgl/style/layers/line_layer.hpp
@@ -28,86 +28,86 @@ public:
     // Layout properties
 
     static PropertyValue<LineCapType> getDefaultLineCap();
-    PropertyValue<LineCapType> getLineCap() const;
-    void setLineCap(PropertyValue<LineCapType>);
+    const PropertyValue<LineCapType>& getLineCap() const;
+    void setLineCap(const PropertyValue<LineCapType>&);
 
     static PropertyValue<LineJoinType> getDefaultLineJoin();
-    PropertyValue<LineJoinType> getLineJoin() const;
-    void setLineJoin(PropertyValue<LineJoinType>);
+    const PropertyValue<LineJoinType>& getLineJoin() const;
+    void setLineJoin(const PropertyValue<LineJoinType>&);
 
     static PropertyValue<float> getDefaultLineMiterLimit();
-    PropertyValue<float> getLineMiterLimit() const;
-    void setLineMiterLimit(PropertyValue<float>);
+    const PropertyValue<float>& getLineMiterLimit() const;
+    void setLineMiterLimit(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultLineRoundLimit();
-    PropertyValue<float> getLineRoundLimit() const;
-    void setLineRoundLimit(PropertyValue<float>);
+    const PropertyValue<float>& getLineRoundLimit() const;
+    void setLineRoundLimit(const PropertyValue<float>&);
 
     // Paint properties
 
     static PropertyValue<float> getDefaultLineOpacity();
-    PropertyValue<float> getLineOpacity() const;
-    void setLineOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getLineOpacity() const;
+    void setLineOpacity(const PropertyValue<float>&);
     void setLineOpacityTransition(const TransitionOptions&);
     TransitionOptions getLineOpacityTransition() const;
 
     static PropertyValue<Color> getDefaultLineColor();
-    PropertyValue<Color> getLineColor() const;
-    void setLineColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getLineColor() const;
+    void setLineColor(const PropertyValue<Color>&);
     void setLineColorTransition(const TransitionOptions&);
     TransitionOptions getLineColorTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultLineTranslate();
-    PropertyValue<std::array<float, 2>> getLineTranslate() const;
-    void setLineTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getLineTranslate() const;
+    void setLineTranslate(const PropertyValue<std::array<float, 2>>&);
     void setLineTranslateTransition(const TransitionOptions&);
     TransitionOptions getLineTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultLineTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getLineTranslateAnchor() const;
-    void setLineTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getLineTranslateAnchor() const;
+    void setLineTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setLineTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getLineTranslateAnchorTransition() const;
 
     static PropertyValue<float> getDefaultLineWidth();
-    PropertyValue<float> getLineWidth() const;
-    void setLineWidth(PropertyValue<float>);
+    const PropertyValue<float>& getLineWidth() const;
+    void setLineWidth(const PropertyValue<float>&);
     void setLineWidthTransition(const TransitionOptions&);
     TransitionOptions getLineWidthTransition() const;
 
     static PropertyValue<float> getDefaultLineGapWidth();
-    PropertyValue<float> getLineGapWidth() const;
-    void setLineGapWidth(PropertyValue<float>);
+    const PropertyValue<float>& getLineGapWidth() const;
+    void setLineGapWidth(const PropertyValue<float>&);
     void setLineGapWidthTransition(const TransitionOptions&);
     TransitionOptions getLineGapWidthTransition() const;
 
     static PropertyValue<float> getDefaultLineOffset();
-    PropertyValue<float> getLineOffset() const;
-    void setLineOffset(PropertyValue<float>);
+    const PropertyValue<float>& getLineOffset() const;
+    void setLineOffset(const PropertyValue<float>&);
     void setLineOffsetTransition(const TransitionOptions&);
     TransitionOptions getLineOffsetTransition() const;
 
     static PropertyValue<float> getDefaultLineBlur();
-    PropertyValue<float> getLineBlur() const;
-    void setLineBlur(PropertyValue<float>);
+    const PropertyValue<float>& getLineBlur() const;
+    void setLineBlur(const PropertyValue<float>&);
     void setLineBlurTransition(const TransitionOptions&);
     TransitionOptions getLineBlurTransition() const;
 
     static PropertyValue<std::vector<float>> getDefaultLineDasharray();
-    PropertyValue<std::vector<float>> getLineDasharray() const;
-    void setLineDasharray(PropertyValue<std::vector<float>>);
+    const PropertyValue<std::vector<float>>& getLineDasharray() const;
+    void setLineDasharray(const PropertyValue<std::vector<float>>&);
     void setLineDasharrayTransition(const TransitionOptions&);
     TransitionOptions getLineDasharrayTransition() const;
 
     static PropertyValue<std::string> getDefaultLinePattern();
-    PropertyValue<std::string> getLinePattern() const;
-    void setLinePattern(PropertyValue<std::string>);
+    const PropertyValue<std::string>& getLinePattern() const;
+    void setLinePattern(const PropertyValue<std::string>&);
     void setLinePatternTransition(const TransitionOptions&);
     TransitionOptions getLinePatternTransition() const;
 
     static ColorRampPropertyValue getDefaultLineGradient();
-    ColorRampPropertyValue getLineGradient() const;
-    void setLineGradient(ColorRampPropertyValue);
+    const ColorRampPropertyValue& getLineGradient() const;
+    void setLineGradient(const ColorRampPropertyValue&);
     void setLineGradientTransition(const TransitionOptions&);
     TransitionOptions getLineGradientTransition() const;
 
diff --git a/include/mbgl/style/layers/raster_layer.hpp b/include/mbgl/style/layers/raster_layer.hpp
index f4736c9dcd..bdd9857c39 100644
--- a/include/mbgl/style/layers/raster_layer.hpp
+++ b/include/mbgl/style/layers/raster_layer.hpp
@@ -25,50 +25,50 @@ public:
     // Paint properties
 
     static PropertyValue<float> getDefaultRasterOpacity();
-    PropertyValue<float> getRasterOpacity() const;
-    void setRasterOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getRasterOpacity() const;
+    void setRasterOpacity(const PropertyValue<float>&);
     void setRasterOpacityTransition(const TransitionOptions&);
     TransitionOptions getRasterOpacityTransition() const;
 
     static PropertyValue<float> getDefaultRasterHueRotate();
-    PropertyValue<float> getRasterHueRotate() const;
-    void setRasterHueRotate(PropertyValue<float>);
+    const PropertyValue<float>& getRasterHueRotate() const;
+    void setRasterHueRotate(const PropertyValue<float>&);
     void setRasterHueRotateTransition(const TransitionOptions&);
     TransitionOptions getRasterHueRotateTransition() const;
 
     static PropertyValue<float> getDefaultRasterBrightnessMin();
-    PropertyValue<float> getRasterBrightnessMin() const;
-    void setRasterBrightnessMin(PropertyValue<float>);
+    const PropertyValue<float>& getRasterBrightnessMin() const;
+    void setRasterBrightnessMin(const PropertyValue<float>&);
     void setRasterBrightnessMinTransition(const TransitionOptions&);
     TransitionOptions getRasterBrightnessMinTransition() const;
 
     static PropertyValue<float> getDefaultRasterBrightnessMax();
-    PropertyValue<float> getRasterBrightnessMax() const;
-    void setRasterBrightnessMax(PropertyValue<float>);
+    const PropertyValue<float>& getRasterBrightnessMax() const;
+    void setRasterBrightnessMax(const PropertyValue<float>&);
     void setRasterBrightnessMaxTransition(const TransitionOptions&);
     TransitionOptions getRasterBrightnessMaxTransition() const;
 
     static PropertyValue<float> getDefaultRasterSaturation();
-    PropertyValue<float> getRasterSaturation() const;
-    void setRasterSaturation(PropertyValue<float>);
+    const PropertyValue<float>& getRasterSaturation() const;
+    void setRasterSaturation(const PropertyValue<float>&);
     void setRasterSaturationTransition(const TransitionOptions&);
     TransitionOptions getRasterSaturationTransition() const;
 
     static PropertyValue<float> getDefaultRasterContrast();
-    PropertyValue<float> getRasterContrast() const;
-    void setRasterContrast(PropertyValue<float>);
+    const PropertyValue<float>& getRasterContrast() const;
+    void setRasterContrast(const PropertyValue<float>&);
     void setRasterContrastTransition(const TransitionOptions&);
     TransitionOptions getRasterContrastTransition() const;
 
     static PropertyValue<RasterResamplingType> getDefaultRasterResampling();
-    PropertyValue<RasterResamplingType> getRasterResampling() const;
-    void setRasterResampling(PropertyValue<RasterResamplingType>);
+    const PropertyValue<RasterResamplingType>& getRasterResampling() const;
+    void setRasterResampling(const PropertyValue<RasterResamplingType>&);
     void setRasterResamplingTransition(const TransitionOptions&);
     TransitionOptions getRasterResamplingTransition() const;
 
     static PropertyValue<float> getDefaultRasterFadeDuration();
-    PropertyValue<float> getRasterFadeDuration() const;
-    void setRasterFadeDuration(PropertyValue<float>);
+    const PropertyValue<float>& getRasterFadeDuration() const;
+    void setRasterFadeDuration(const PropertyValue<float>&);
     void setRasterFadeDurationTransition(const TransitionOptions&);
     TransitionOptions getRasterFadeDurationTransition() const;
 
diff --git a/include/mbgl/style/layers/symbol_layer.hpp b/include/mbgl/style/layers/symbol_layer.hpp
index 35fe72e6bf..c7082f232d 100644
--- a/include/mbgl/style/layers/symbol_layer.hpp
+++ b/include/mbgl/style/layers/symbol_layer.hpp
@@ -27,244 +27,244 @@ public:
     // Layout properties
 
     static PropertyValue<SymbolPlacementType> getDefaultSymbolPlacement();
-    PropertyValue<SymbolPlacementType> getSymbolPlacement() const;
-    void setSymbolPlacement(PropertyValue<SymbolPlacementType>);
+    const PropertyValue<SymbolPlacementType>& getSymbolPlacement() const;
+    void setSymbolPlacement(const PropertyValue<SymbolPlacementType>&);
 
     static PropertyValue<float> getDefaultSymbolSpacing();
-    PropertyValue<float> getSymbolSpacing() const;
-    void setSymbolSpacing(PropertyValue<float>);
+    const PropertyValue<float>& getSymbolSpacing() const;
+    void setSymbolSpacing(const PropertyValue<float>&);
 
     static PropertyValue<bool> getDefaultSymbolAvoidEdges();
-    PropertyValue<bool> getSymbolAvoidEdges() const;
-    void setSymbolAvoidEdges(PropertyValue<bool>);
+    const PropertyValue<bool>& getSymbolAvoidEdges() const;
+    void setSymbolAvoidEdges(const PropertyValue<bool>&);
 
     static PropertyValue<SymbolZOrderType> getDefaultSymbolZOrder();
-    PropertyValue<SymbolZOrderType> getSymbolZOrder() const;
-    void setSymbolZOrder(PropertyValue<SymbolZOrderType>);
+    const PropertyValue<SymbolZOrderType>& getSymbolZOrder() const;
+    void setSymbolZOrder(const PropertyValue<SymbolZOrderType>&);
 
     static PropertyValue<bool> getDefaultIconAllowOverlap();
-    PropertyValue<bool> getIconAllowOverlap() const;
-    void setIconAllowOverlap(PropertyValue<bool>);
+    const PropertyValue<bool>& getIconAllowOverlap() const;
+    void setIconAllowOverlap(const PropertyValue<bool>&);
 
     static PropertyValue<bool> getDefaultIconIgnorePlacement();
-    PropertyValue<bool> getIconIgnorePlacement() const;
-    void setIconIgnorePlacement(PropertyValue<bool>);
+    const PropertyValue<bool>& getIconIgnorePlacement() const;
+    void setIconIgnorePlacement(const PropertyValue<bool>&);
 
     static PropertyValue<bool> getDefaultIconOptional();
-    PropertyValue<bool> getIconOptional() const;
-    void setIconOptional(PropertyValue<bool>);
+    const PropertyValue<bool>& getIconOptional() const;
+    void setIconOptional(const PropertyValue<bool>&);
 
     static PropertyValue<AlignmentType> getDefaultIconRotationAlignment();
-    PropertyValue<AlignmentType> getIconRotationAlignment() const;
-    void setIconRotationAlignment(PropertyValue<AlignmentType>);
+    const PropertyValue<AlignmentType>& getIconRotationAlignment() const;
+    void setIconRotationAlignment(const PropertyValue<AlignmentType>&);
 
     static PropertyValue<float> getDefaultIconSize();
-    PropertyValue<float> getIconSize() const;
-    void setIconSize(PropertyValue<float>);
+    const PropertyValue<float>& getIconSize() const;
+    void setIconSize(const PropertyValue<float>&);
 
     static PropertyValue<IconTextFitType> getDefaultIconTextFit();
-    PropertyValue<IconTextFitType> getIconTextFit() const;
-    void setIconTextFit(PropertyValue<IconTextFitType>);
+    const PropertyValue<IconTextFitType>& getIconTextFit() const;
+    void setIconTextFit(const PropertyValue<IconTextFitType>&);
 
     static PropertyValue<std::array<float, 4>> getDefaultIconTextFitPadding();
-    PropertyValue<std::array<float, 4>> getIconTextFitPadding() const;
-    void setIconTextFitPadding(PropertyValue<std::array<float, 4>>);
+    const PropertyValue<std::array<float, 4>>& getIconTextFitPadding() const;
+    void setIconTextFitPadding(const PropertyValue<std::array<float, 4>>&);
 
     static PropertyValue<std::string> getDefaultIconImage();
-    PropertyValue<std::string> getIconImage() const;
-    void setIconImage(PropertyValue<std::string>);
+    const PropertyValue<std::string>& getIconImage() const;
+    void setIconImage(const PropertyValue<std::string>&);
 
     static PropertyValue<float> getDefaultIconRotate();
-    PropertyValue<float> getIconRotate() const;
-    void setIconRotate(PropertyValue<float>);
+    const PropertyValue<float>& getIconRotate() const;
+    void setIconRotate(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultIconPadding();
-    PropertyValue<float> getIconPadding() const;
-    void setIconPadding(PropertyValue<float>);
+    const PropertyValue<float>& getIconPadding() const;
+    void setIconPadding(const PropertyValue<float>&);
 
     static PropertyValue<bool> getDefaultIconKeepUpright();
-    PropertyValue<bool> getIconKeepUpright() const;
-    void setIconKeepUpright(PropertyValue<bool>);
+    const PropertyValue<bool>& getIconKeepUpright() const;
+    void setIconKeepUpright(const PropertyValue<bool>&);
 
     static PropertyValue<std::array<float, 2>> getDefaultIconOffset();
-    PropertyValue<std::array<float, 2>> getIconOffset() const;
-    void setIconOffset(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getIconOffset() const;
+    void setIconOffset(const PropertyValue<std::array<float, 2>>&);
 
     static PropertyValue<SymbolAnchorType> getDefaultIconAnchor();
-    PropertyValue<SymbolAnchorType> getIconAnchor() const;
-    void setIconAnchor(PropertyValue<SymbolAnchorType>);
+    const PropertyValue<SymbolAnchorType>& getIconAnchor() const;
+    void setIconAnchor(const PropertyValue<SymbolAnchorType>&);
 
     static PropertyValue<AlignmentType> getDefaultIconPitchAlignment();
-    PropertyValue<AlignmentType> getIconPitchAlignment() const;
-    void setIconPitchAlignment(PropertyValue<AlignmentType>);
+    const PropertyValue<AlignmentType>& getIconPitchAlignment() const;
+    void setIconPitchAlignment(const PropertyValue<AlignmentType>&);
 
     static PropertyValue<AlignmentType> getDefaultTextPitchAlignment();
-    PropertyValue<AlignmentType> getTextPitchAlignment() const;
-    void setTextPitchAlignment(PropertyValue<AlignmentType>);
+    const PropertyValue<AlignmentType>& getTextPitchAlignment() const;
+    void setTextPitchAlignment(const PropertyValue<AlignmentType>&);
 
     static PropertyValue<AlignmentType> getDefaultTextRotationAlignment();
-    PropertyValue<AlignmentType> getTextRotationAlignment() const;
-    void setTextRotationAlignment(PropertyValue<AlignmentType>);
+    const PropertyValue<AlignmentType>& getTextRotationAlignment() const;
+    void setTextRotationAlignment(const PropertyValue<AlignmentType>&);
 
     static PropertyValue<expression::Formatted> getDefaultTextField();
-    PropertyValue<expression::Formatted> getTextField() const;
-    void setTextField(PropertyValue<expression::Formatted>);
+    const PropertyValue<expression::Formatted>& getTextField() const;
+    void setTextField(const PropertyValue<expression::Formatted>&);
 
     static PropertyValue<std::vector<std::string>> getDefaultTextFont();
-    PropertyValue<std::vector<std::string>> getTextFont() const;
-    void setTextFont(PropertyValue<std::vector<std::string>>);
+    const PropertyValue<std::vector<std::string>>& getTextFont() const;
+    void setTextFont(const PropertyValue<std::vector<std::string>>&);
 
     static PropertyValue<float> getDefaultTextSize();
-    PropertyValue<float> getTextSize() const;
-    void setTextSize(PropertyValue<float>);
+    const PropertyValue<float>& getTextSize() const;
+    void setTextSize(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultTextMaxWidth();
-    PropertyValue<float> getTextMaxWidth() const;
-    void setTextMaxWidth(PropertyValue<float>);
+    const PropertyValue<float>& getTextMaxWidth() const;
+    void setTextMaxWidth(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultTextLineHeight();
-    PropertyValue<float> getTextLineHeight() const;
-    void setTextLineHeight(PropertyValue<float>);
+    const PropertyValue<float>& getTextLineHeight() const;
+    void setTextLineHeight(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultTextLetterSpacing();
-    PropertyValue<float> getTextLetterSpacing() const;
-    void setTextLetterSpacing(PropertyValue<float>);
+    const PropertyValue<float>& getTextLetterSpacing() const;
+    void setTextLetterSpacing(const PropertyValue<float>&);
 
     static PropertyValue<TextJustifyType> getDefaultTextJustify();
-    PropertyValue<TextJustifyType> getTextJustify() const;
-    void setTextJustify(PropertyValue<TextJustifyType>);
+    const PropertyValue<TextJustifyType>& getTextJustify() const;
+    void setTextJustify(const PropertyValue<TextJustifyType>&);
 
     static PropertyValue<float> getDefaultTextRadialOffset();
-    PropertyValue<float> getTextRadialOffset() const;
-    void setTextRadialOffset(PropertyValue<float>);
+    const PropertyValue<float>& getTextRadialOffset() const;
+    void setTextRadialOffset(const PropertyValue<float>&);
 
     static PropertyValue<std::vector<TextVariableAnchorType>> getDefaultTextVariableAnchor();
-    PropertyValue<std::vector<TextVariableAnchorType>> getTextVariableAnchor() const;
-    void setTextVariableAnchor(PropertyValue<std::vector<TextVariableAnchorType>>);
+    const PropertyValue<std::vector<TextVariableAnchorType>>& getTextVariableAnchor() const;
+    void setTextVariableAnchor(const PropertyValue<std::vector<TextVariableAnchorType>>&);
 
     static PropertyValue<SymbolAnchorType> getDefaultTextAnchor();
-    PropertyValue<SymbolAnchorType> getTextAnchor() const;
-    void setTextAnchor(PropertyValue<SymbolAnchorType>);
+    const PropertyValue<SymbolAnchorType>& getTextAnchor() const;
+    void setTextAnchor(const PropertyValue<SymbolAnchorType>&);
 
     static PropertyValue<float> getDefaultTextMaxAngle();
-    PropertyValue<float> getTextMaxAngle() const;
-    void setTextMaxAngle(PropertyValue<float>);
+    const PropertyValue<float>& getTextMaxAngle() const;
+    void setTextMaxAngle(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultTextRotate();
-    PropertyValue<float> getTextRotate() const;
-    void setTextRotate(PropertyValue<float>);
+    const PropertyValue<float>& getTextRotate() const;
+    void setTextRotate(const PropertyValue<float>&);
 
     static PropertyValue<float> getDefaultTextPadding();
-    PropertyValue<float> getTextPadding() const;
-    void setTextPadding(PropertyValue<float>);
+    const PropertyValue<float>& getTextPadding() const;
+    void setTextPadding(const PropertyValue<float>&);
 
     static PropertyValue<bool> getDefaultTextKeepUpright();
-    PropertyValue<bool> getTextKeepUpright() const;
-    void setTextKeepUpright(PropertyValue<bool>);
+    const PropertyValue<bool>& getTextKeepUpright() const;
+    void setTextKeepUpright(const PropertyValue<bool>&);
 
     static PropertyValue<TextTransformType> getDefaultTextTransform();
-    PropertyValue<TextTransformType> getTextTransform() const;
-    void setTextTransform(PropertyValue<TextTransformType>);
+    const PropertyValue<TextTransformType>& getTextTransform() const;
+    void setTextTransform(const PropertyValue<TextTransformType>&);
 
     static PropertyValue<std::array<float, 2>> getDefaultTextOffset();
-    PropertyValue<std::array<float, 2>> getTextOffset() const;
-    void setTextOffset(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getTextOffset() const;
+    void setTextOffset(const PropertyValue<std::array<float, 2>>&);
 
     static PropertyValue<bool> getDefaultTextAllowOverlap();
-    PropertyValue<bool> getTextAllowOverlap() const;
-    void setTextAllowOverlap(PropertyValue<bool>);
+    const PropertyValue<bool>& getTextAllowOverlap() const;
+    void setTextAllowOverlap(const PropertyValue<bool>&);
 
     static PropertyValue<bool> getDefaultTextIgnorePlacement();
-    PropertyValue<bool> getTextIgnorePlacement() const;
-    void setTextIgnorePlacement(PropertyValue<bool>);
+    const PropertyValue<bool>& getTextIgnorePlacement() const;
+    void setTextIgnorePlacement(const PropertyValue<bool>&);
 
     static PropertyValue<bool> getDefaultTextOptional();
-    PropertyValue<bool> getTextOptional() const;
-    void setTextOptional(PropertyValue<bool>);
+    const PropertyValue<bool>& getTextOptional() const;
+    void setTextOptional(const PropertyValue<bool>&);
 
     // Paint properties
 
     static PropertyValue<float> getDefaultIconOpacity();
-    PropertyValue<float> getIconOpacity() const;
-    void setIconOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getIconOpacity() const;
+    void setIconOpacity(const PropertyValue<float>&);
     void setIconOpacityTransition(const TransitionOptions&);
     TransitionOptions getIconOpacityTransition() const;
 
     static PropertyValue<Color> getDefaultIconColor();
-    PropertyValue<Color> getIconColor() const;
-    void setIconColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getIconColor() const;
+    void setIconColor(const PropertyValue<Color>&);
     void setIconColorTransition(const TransitionOptions&);
     TransitionOptions getIconColorTransition() const;
 
     static PropertyValue<Color> getDefaultIconHaloColor();
-    PropertyValue<Color> getIconHaloColor() const;
-    void setIconHaloColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getIconHaloColor() const;
+    void setIconHaloColor(const PropertyValue<Color>&);
     void setIconHaloColorTransition(const TransitionOptions&);
     TransitionOptions getIconHaloColorTransition() const;
 
     static PropertyValue<float> getDefaultIconHaloWidth();
-    PropertyValue<float> getIconHaloWidth() const;
-    void setIconHaloWidth(PropertyValue<float>);
+    const PropertyValue<float>& getIconHaloWidth() const;
+    void setIconHaloWidth(const PropertyValue<float>&);
     void setIconHaloWidthTransition(const TransitionOptions&);
     TransitionOptions getIconHaloWidthTransition() const;
 
     static PropertyValue<float> getDefaultIconHaloBlur();
-    PropertyValue<float> getIconHaloBlur() const;
-    void setIconHaloBlur(PropertyValue<float>);
+    const PropertyValue<float>& getIconHaloBlur() const;
+    void setIconHaloBlur(const PropertyValue<float>&);
     void setIconHaloBlurTransition(const TransitionOptions&);
     TransitionOptions getIconHaloBlurTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultIconTranslate();
-    PropertyValue<std::array<float, 2>> getIconTranslate() const;
-    void setIconTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getIconTranslate() const;
+    void setIconTranslate(const PropertyValue<std::array<float, 2>>&);
     void setIconTranslateTransition(const TransitionOptions&);
     TransitionOptions getIconTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultIconTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getIconTranslateAnchor() const;
-    void setIconTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getIconTranslateAnchor() const;
+    void setIconTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setIconTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getIconTranslateAnchorTransition() const;
 
     static PropertyValue<float> getDefaultTextOpacity();
-    PropertyValue<float> getTextOpacity() const;
-    void setTextOpacity(PropertyValue<float>);
+    const PropertyValue<float>& getTextOpacity() const;
+    void setTextOpacity(const PropertyValue<float>&);
     void setTextOpacityTransition(const TransitionOptions&);
     TransitionOptions getTextOpacityTransition() const;
 
     static PropertyValue<Color> getDefaultTextColor();
-    PropertyValue<Color> getTextColor() const;
-    void setTextColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getTextColor() const;
+    void setTextColor(const PropertyValue<Color>&);
     void setTextColorTransition(const TransitionOptions&);
     TransitionOptions getTextColorTransition() const;
 
     static PropertyValue<Color> getDefaultTextHaloColor();
-    PropertyValue<Color> getTextHaloColor() const;
-    void setTextHaloColor(PropertyValue<Color>);
+    const PropertyValue<Color>& getTextHaloColor() const;
+    void setTextHaloColor(const PropertyValue<Color>&);
     void setTextHaloColorTransition(const TransitionOptions&);
     TransitionOptions getTextHaloColorTransition() const;
 
     static PropertyValue<float> getDefaultTextHaloWidth();
-    PropertyValue<float> getTextHaloWidth() const;
-    void setTextHaloWidth(PropertyValue<float>);
+    const PropertyValue<float>& getTextHaloWidth() const;
+    void setTextHaloWidth(const PropertyValue<float>&);
     void setTextHaloWidthTransition(const TransitionOptions&);
     TransitionOptions getTextHaloWidthTransition() const;
 
     static PropertyValue<float> getDefaultTextHaloBlur();
-    PropertyValue<float> getTextHaloBlur() const;
-    void setTextHaloBlur(PropertyValue<float>);
+    const PropertyValue<float>& getTextHaloBlur() const;
+    void setTextHaloBlur(const PropertyValue<float>&);
     void setTextHaloBlurTransition(const TransitionOptions&);
     TransitionOptions getTextHaloBlurTransition() const;
 
     static PropertyValue<std::array<float, 2>> getDefaultTextTranslate();
-    PropertyValue<std::array<float, 2>> getTextTranslate() const;
-    void setTextTranslate(PropertyValue<std::array<float, 2>>);
+    const PropertyValue<std::array<float, 2>>& getTextTranslate() const;
+    void setTextTranslate(const PropertyValue<std::array<float, 2>>&);
     void setTextTranslateTransition(const TransitionOptions&);
     TransitionOptions getTextTranslateTransition() const;
 
     static PropertyValue<TranslateAnchorType> getDefaultTextTranslateAnchor();
-    PropertyValue<TranslateAnchorType> getTextTranslateAnchor() const;
-    void setTextTranslateAnchor(PropertyValue<TranslateAnchorType>);
+    const PropertyValue<TranslateAnchorType>& getTextTranslateAnchor() const;
+    void setTextTranslateAnchor(const PropertyValue<TranslateAnchorType>&);
     void setTextTranslateAnchorTransition(const TransitionOptions&);
     TransitionOptions getTextTranslateAnchorTransition() const;