[ios, macos] Avoid unsafe cast when removing style layers (#7227)

This updates the code generation for style layers to add a test to check
that the style object returned from mbgl can be safely cast into the
expected type so ownership can be returned to the caller when removing
layers.

This scenario was previously possible if a layer of type T was
added before a layer of type U but both layers shared the same
identifier. In that case, if the pointer to the second layer of type U
was used to remove a layer, a runtime exception would occur since mbgl
returns the layer with type T (the first one added).

Now, an exception will still occur if layers with the same
identifier are manipulated as described above but it is done as part of
a validation check for all public style layer methods at the Darwin
platform level. The NSException attempts to warn developers about using
and reusing style identifiers to avoid this issue in the first place.

platform/darwin/src/MGLBackgroundStyleLayer.mm

@@ -50,42 +50,65 @@
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::BackgroundLayer> &>(removedLayer));
+
+    mbgl::style::BackgroundLayer *layer = dynamic_cast<mbgl::style::BackgroundLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::BackgroundLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setBackgroundColor:(MGLStyleValue<MGLColor *> *)backgroundColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(backgroundColor);
     _rawLayer->setBackgroundColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)backgroundColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getBackgroundColor() ?: _rawLayer->getDefaultBackgroundColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setBackgroundOpacity:(MGLStyleValue<NSNumber *> *)backgroundOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(backgroundOpacity);
     _rawLayer->setBackgroundOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)backgroundOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getBackgroundOpacity() ?: _rawLayer->getDefaultBackgroundOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setBackgroundPattern:(MGLStyleValue<NSString *> *)backgroundPattern {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::string, NSString *>().toPropertyValue(backgroundPattern);
     _rawLayer->setBackgroundPattern(mbglValue);
 }
 
 - (MGLStyleValue<NSString *> *)backgroundPattern {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getBackgroundPattern() ?: _rawLayer->getDefaultBackgroundPattern();
     return MGLStyleValueTransformer<std::string, NSString *>().toStyleValue(propertyValue);
 }

platform/darwin/src/MGLCircleStyleLayer.mm

@@ -45,22 +45,30 @@ namespace mbgl {
 }
 - (NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     auto layerID = _rawLayer->getSourceLayer();
     return layerID.empty() ? nil : @(layerID.c_str());
 }
 
 - (void)setSourceLayerIdentifier:(NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setSourceLayer(sourceLayerIdentifier.UTF8String ?: "");
 }
 
 - (void)setPredicate:(NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setFilter(predicate.mgl_filter);
 }
 
 - (NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     return [NSPredicate mgl_predicateWithFilter:_rawLayer->getFilter()];
 }
 #pragma mark -  Adding to and removing from a map view
@@ -82,82 +90,121 @@ namespace mbgl {
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::CircleLayer> &>(removedLayer));
+
+    mbgl::style::CircleLayer *layer = dynamic_cast<mbgl::style::CircleLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::CircleLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setCircleBlur:(MGLStyleValue<NSNumber *> *)circleBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(circleBlur);
     _rawLayer->setCircleBlur(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)circleBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleBlur() ?: _rawLayer->getDefaultCircleBlur();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setCircleColor:(MGLStyleValue<MGLColor *> *)circleColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(circleColor);
     _rawLayer->setCircleColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)circleColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleColor() ?: _rawLayer->getDefaultCircleColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setCircleOpacity:(MGLStyleValue<NSNumber *> *)circleOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(circleOpacity);
     _rawLayer->setCircleOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)circleOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleOpacity() ?: _rawLayer->getDefaultCircleOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setCirclePitchScale:(MGLStyleValue<NSValue *> *)circlePitchScale {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::CirclePitchScaleType, NSValue *, mbgl::style::CirclePitchScaleType, MGLCirclePitchScale>().toEnumPropertyValue(circlePitchScale);
     _rawLayer->setCirclePitchScale(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)circlePitchScale {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCirclePitchScale() ?: _rawLayer->getDefaultCirclePitchScale();
     return MGLStyleValueTransformer<mbgl::style::CirclePitchScaleType, NSValue *, mbgl::style::CirclePitchScaleType, MGLCirclePitchScale>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setCircleRadius:(MGLStyleValue<NSNumber *> *)circleRadius {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(circleRadius);
     _rawLayer->setCircleRadius(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)circleRadius {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleRadius() ?: _rawLayer->getDefaultCircleRadius();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setCircleTranslate:(MGLStyleValue<NSValue *> *)circleTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(circleTranslate);
     _rawLayer->setCircleTranslate(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)circleTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleTranslate() ?: _rawLayer->getDefaultCircleTranslate();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setCircleTranslateAnchor:(MGLStyleValue<NSValue *> *)circleTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLCircleTranslateAnchor>().toEnumPropertyValue(circleTranslateAnchor);
     _rawLayer->setCircleTranslateAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)circleTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getCircleTranslateAnchor() ?: _rawLayer->getDefaultCircleTranslateAnchor();
     return MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLCircleTranslateAnchor>().toEnumStyleValue(propertyValue);
 }

platform/darwin/src/MGLFillStyleLayer.mm

@@ -40,22 +40,30 @@ namespace mbgl {
 }
 - (NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     auto layerID = _rawLayer->getSourceLayer();
     return layerID.empty() ? nil : @(layerID.c_str());
 }
 
 - (void)setSourceLayerIdentifier:(NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setSourceLayer(sourceLayerIdentifier.UTF8String ?: "");
 }
 
 - (void)setPredicate:(NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setFilter(predicate.mgl_filter);
 }
 
 - (NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     return [NSPredicate mgl_predicateWithFilter:_rawLayer->getFilter()];
 }
 #pragma mark -  Adding to and removing from a map view
@@ -77,82 +85,121 @@ namespace mbgl {
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::FillLayer> &>(removedLayer));
+
+    mbgl::style::FillLayer *layer = dynamic_cast<mbgl::style::FillLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::FillLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setFillAntialias:(MGLStyleValue<NSNumber *> *)fillAntialias {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(fillAntialias);
     _rawLayer->setFillAntialias(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)fillAntialias {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillAntialias() ?: _rawLayer->getDefaultFillAntialias();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillColor:(MGLStyleValue<MGLColor *> *)fillColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(fillColor);
     _rawLayer->setFillColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)fillColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillColor() ?: _rawLayer->getDefaultFillColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillOpacity:(MGLStyleValue<NSNumber *> *)fillOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(fillOpacity);
     _rawLayer->setFillOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)fillOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillOpacity() ?: _rawLayer->getDefaultFillOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillOutlineColor:(MGLStyleValue<MGLColor *> *)fillOutlineColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(fillOutlineColor);
     _rawLayer->setFillOutlineColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)fillOutlineColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillOutlineColor() ?: _rawLayer->getDefaultFillOutlineColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillPattern:(MGLStyleValue<NSString *> *)fillPattern {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::string, NSString *>().toPropertyValue(fillPattern);
     _rawLayer->setFillPattern(mbglValue);
 }
 
 - (MGLStyleValue<NSString *> *)fillPattern {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillPattern() ?: _rawLayer->getDefaultFillPattern();
     return MGLStyleValueTransformer<std::string, NSString *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillTranslate:(MGLStyleValue<NSValue *> *)fillTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(fillTranslate);
     _rawLayer->setFillTranslate(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)fillTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillTranslate() ?: _rawLayer->getDefaultFillTranslate();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setFillTranslateAnchor:(MGLStyleValue<NSValue *> *)fillTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLFillTranslateAnchor>().toEnumPropertyValue(fillTranslateAnchor);
     _rawLayer->setFillTranslateAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)fillTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getFillTranslateAnchor() ?: _rawLayer->getDefaultFillTranslateAnchor();
     return MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLFillTranslateAnchor>().toEnumStyleValue(propertyValue);
 }

platform/darwin/src/MGLLineStyleLayer.mm

@@ -52,22 +52,30 @@ namespace mbgl {
 }
 - (NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     auto layerID = _rawLayer->getSourceLayer();
     return layerID.empty() ? nil : @(layerID.c_str());
 }
 
 - (void)setSourceLayerIdentifier:(NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setSourceLayer(sourceLayerIdentifier.UTF8String ?: "");
 }
 
 - (void)setPredicate:(NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setFilter(predicate.mgl_filter);
 }
 
 - (NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     return [NSPredicate mgl_predicateWithFilter:_rawLayer->getFilter()];
 }
 #pragma mark -  Adding to and removing from a map view
@@ -89,52 +97,79 @@ namespace mbgl {
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::LineLayer> &>(removedLayer));
+
+    mbgl::style::LineLayer *layer = dynamic_cast<mbgl::style::LineLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::LineLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Layout Attributes
 
 - (void)setLineCap:(MGLStyleValue<NSValue *> *)lineCap {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::LineCapType, NSValue *, mbgl::style::LineCapType, MGLLineCap>().toEnumPropertyValue(lineCap);
     _rawLayer->setLineCap(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)lineCap {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineCap() ?: _rawLayer->getDefaultLineCap();
     return MGLStyleValueTransformer<mbgl::style::LineCapType, NSValue *, mbgl::style::LineCapType, MGLLineCap>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setLineJoin:(MGLStyleValue<NSValue *> *)lineJoin {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::LineJoinType, NSValue *, mbgl::style::LineJoinType, MGLLineJoin>().toEnumPropertyValue(lineJoin);
     _rawLayer->setLineJoin(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)lineJoin {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineJoin() ?: _rawLayer->getDefaultLineJoin();
     return MGLStyleValueTransformer<mbgl::style::LineJoinType, NSValue *, mbgl::style::LineJoinType, MGLLineJoin>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setLineMiterLimit:(MGLStyleValue<NSNumber *> *)lineMiterLimit {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineMiterLimit);
     _rawLayer->setLineMiterLimit(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineMiterLimit {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineMiterLimit() ?: _rawLayer->getDefaultLineMiterLimit();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineRoundLimit:(MGLStyleValue<NSNumber *> *)lineRoundLimit {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineRoundLimit);
     _rawLayer->setLineRoundLimit(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineRoundLimit {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineRoundLimit() ?: _rawLayer->getDefaultLineRoundLimit();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
@@ -142,101 +177,141 @@ namespace mbgl {
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setLineBlur:(MGLStyleValue<NSNumber *> *)lineBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineBlur);
     _rawLayer->setLineBlur(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineBlur() ?: _rawLayer->getDefaultLineBlur();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineColor:(MGLStyleValue<MGLColor *> *)lineColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(lineColor);
     _rawLayer->setLineColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)lineColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineColor() ?: _rawLayer->getDefaultLineColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineDasharray:(MGLStyleValue<NSArray<NSNumber *> *> *)lineDasharray {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::vector<float>, NSArray<NSNumber *> *, float>().toPropertyValue(lineDasharray);
     _rawLayer->setLineDasharray(mbglValue);
 }
 
 - (MGLStyleValue<NSArray<NSNumber *> *> *)lineDasharray {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineDasharray() ?: _rawLayer->getDefaultLineDasharray();
     return MGLStyleValueTransformer<std::vector<float>, NSArray<NSNumber *> *, float>().toStyleValue(propertyValue);
 }
 
 - (void)setLineGapWidth:(MGLStyleValue<NSNumber *> *)lineGapWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineGapWidth);
     _rawLayer->setLineGapWidth(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineGapWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineGapWidth() ?: _rawLayer->getDefaultLineGapWidth();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineOffset:(MGLStyleValue<NSNumber *> *)lineOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineOffset);
     _rawLayer->setLineOffset(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineOffset() ?: _rawLayer->getDefaultLineOffset();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineOpacity:(MGLStyleValue<NSNumber *> *)lineOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineOpacity);
     _rawLayer->setLineOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineOpacity() ?: _rawLayer->getDefaultLineOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setLinePattern:(MGLStyleValue<NSString *> *)linePattern {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::string, NSString *>().toPropertyValue(linePattern);
     _rawLayer->setLinePattern(mbglValue);
 }
 
 - (MGLStyleValue<NSString *> *)linePattern {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLinePattern() ?: _rawLayer->getDefaultLinePattern();
     return MGLStyleValueTransformer<std::string, NSString *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineTranslate:(MGLStyleValue<NSValue *> *)lineTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(lineTranslate);
     _rawLayer->setLineTranslate(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)lineTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineTranslate() ?: _rawLayer->getDefaultLineTranslate();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setLineTranslateAnchor:(MGLStyleValue<NSValue *> *)lineTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLLineTranslateAnchor>().toEnumPropertyValue(lineTranslateAnchor);
     _rawLayer->setLineTranslateAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)lineTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineTranslateAnchor() ?: _rawLayer->getDefaultLineTranslateAnchor();
     return MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLLineTranslateAnchor>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setLineWidth:(MGLStyleValue<NSNumber *> *)lineWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(lineWidth);
     _rawLayer->setLineWidth(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)lineWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getLineWidth() ?: _rawLayer->getDefaultLineWidth();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }

platform/darwin/src/MGLRasterStyleLayer.mm

@@ -49,82 +49,121 @@
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::RasterLayer> &>(removedLayer));
+
+    mbgl::style::RasterLayer *layer = dynamic_cast<mbgl::style::RasterLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::RasterLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setMaximumRasterBrightness:(MGLStyleValue<NSNumber *> *)maximumRasterBrightness {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(maximumRasterBrightness);
     _rawLayer->setRasterBrightnessMax(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)maximumRasterBrightness {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterBrightnessMax() ?: _rawLayer->getDefaultRasterBrightnessMax();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setMinimumRasterBrightness:(MGLStyleValue<NSNumber *> *)minimumRasterBrightness {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(minimumRasterBrightness);
     _rawLayer->setRasterBrightnessMin(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)minimumRasterBrightness {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterBrightnessMin() ?: _rawLayer->getDefaultRasterBrightnessMin();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setRasterContrast:(MGLStyleValue<NSNumber *> *)rasterContrast {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(rasterContrast);
     _rawLayer->setRasterContrast(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)rasterContrast {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterContrast() ?: _rawLayer->getDefaultRasterContrast();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setRasterFadeDuration:(MGLStyleValue<NSNumber *> *)rasterFadeDuration {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(rasterFadeDuration);
     _rawLayer->setRasterFadeDuration(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)rasterFadeDuration {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterFadeDuration() ?: _rawLayer->getDefaultRasterFadeDuration();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setRasterHueRotate:(MGLStyleValue<NSNumber *> *)rasterHueRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(rasterHueRotate);
     _rawLayer->setRasterHueRotate(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)rasterHueRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterHueRotate() ?: _rawLayer->getDefaultRasterHueRotate();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setRasterOpacity:(MGLStyleValue<NSNumber *> *)rasterOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(rasterOpacity);
     _rawLayer->setRasterOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)rasterOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterOpacity() ?: _rawLayer->getDefaultRasterOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setRasterSaturation:(MGLStyleValue<NSNumber *> *)rasterSaturation {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(rasterSaturation);
     _rawLayer->setRasterSaturation(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)rasterSaturation {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getRasterSaturation() ?: _rawLayer->getDefaultRasterSaturation();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }

platform/darwin/src/MGLStyleLayer.mm

@@ -3,10 +3,6 @@
 
 #include <mbgl/style/layer.hpp>
 
-@interface MGLStyleLayer ()
-
-@end
-
 @implementation MGLStyleLayer
 
 - (instancetype)initWithIdentifier:(NSString *)identifier
@@ -19,6 +15,8 @@
 
 - (void)setVisible:(BOOL)visible
 {
+    MGLAssertStyleLayerIsValid();
+
     mbgl::style::VisibilityType v = visible
     ? mbgl::style::VisibilityType::Visible
     : mbgl::style::VisibilityType::None;
@@ -27,27 +25,37 @@
 
 - (BOOL)isVisible
 {
+    MGLAssertStyleLayerIsValid();
+
     mbgl::style::VisibilityType v = self.rawLayer->getVisibility();
     return (v == mbgl::style::VisibilityType::Visible);
 }
 
 - (void)setMaximumZoomLevel:(float)maximumZoomLevel
 {
+    MGLAssertStyleLayerIsValid();
+
     self.rawLayer->setMaxZoom(maximumZoomLevel);
 }
 
 - (float)maximumZoomLevel
 {
+    MGLAssertStyleLayerIsValid();
+
     return self.rawLayer->getMaxZoom();
 }
 
 - (void)setMinimumZoomLevel:(float)minimumZoomLevel
 {
+    MGLAssertStyleLayerIsValid();
+
     self.rawLayer->setMinZoom(minimumZoomLevel);
 }
 
 - (float)minimumZoomLevel
 {
+    MGLAssertStyleLayerIsValid();
+    
     return self.rawLayer->getMinZoom();
 }
 

platform/darwin/src/MGLStyleLayer.mm.ejs

@@ -81,22 +81,30 @@ namespace mbgl {
 <% if (type !== 'background' && type !== 'raster') { -%>
 - (NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     auto layerID = _rawLayer->getSourceLayer();
     return layerID.empty() ? nil : @(layerID.c_str());
 }
 
 - (void)setSourceLayerIdentifier:(NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setSourceLayer(sourceLayerIdentifier.UTF8String ?: "");
 }
 
 - (void)setPredicate:(NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setFilter(predicate.mgl_filter);
 }
 
 - (NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     return [NSPredicate mgl_predicateWithFilter:_rawLayer->getFilter()];
 }
 <% } -%>
@@ -119,11 +127,22 @@ namespace mbgl {
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::<%- camelize(type) %>Layer> &>(removedLayer));
+
+    mbgl::style::<%- camelize(type) %>Layer *layer = dynamic_cast<mbgl::style::<%- camelize(type) %>Layer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::<%- camelize(type) %>Layer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
@@ -132,6 +151,8 @@ namespace mbgl {
 
 <% for (const property of layoutProperties) { -%>
 - (void)set<%- camelize(property.name) %>:(MGLStyleValue<<%- propertyType(property, true) %>> *)<%- objCName(property) %> {
+    MGLAssertStyleLayerIsValid();
+
 <% if (property.type == "enum") { -%>
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::<%- mbglType(property) %>, NSValue *, mbgl::style::<%- mbglType(property) %>, MGL<%- camelize(originalPropertyName(property)) %>>().toEnumPropertyValue(<%- objCName(property) %>);
     _rawLayer->set<%- camelize(originalPropertyName(property)) %>(mbglValue);
@@ -142,6 +163,8 @@ namespace mbgl {
 }
 
 - (MGLStyleValue<<%- propertyType(property, true) %>> *)<%- objCName(property) %> {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->get<%- camelize(originalPropertyName(property)) %>() ?: _rawLayer->getDefault<%- camelize(originalPropertyName(property)) %>();
 <% if (property.type == "enum") { -%>
     return MGLStyleValueTransformer<mbgl::style::<%- mbglType(property) %>, NSValue *, mbgl::style::<%- mbglType(property) %>, MGL<%- camelize(originalPropertyName(property)) %>>().toEnumStyleValue(propertyValue);
@@ -157,6 +180,8 @@ namespace mbgl {
 
 <% for (const property of paintProperties) { -%>
 - (void)set<%- camelize(property.name) %>:(MGLStyleValue<<%- propertyType(property, true) %>> *)<%- objCName(property) %> {
+    MGLAssertStyleLayerIsValid();
+
 <% if (property.type == "enum") { -%>
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::<%- mbglType(property) %>, NSValue *, mbgl::style::<%- mbglType(property) %>, MGL<%- camelize(originalPropertyName(property)) %>>().toEnumPropertyValue(<%- objCName(property) %>);
     _rawLayer->set<%- camelize(originalPropertyName(property)) %>(mbglValue);
@@ -167,6 +192,8 @@ namespace mbgl {
 }
 
 - (MGLStyleValue<<%- propertyType(property, true) %>> *)<%- objCName(property) %> {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->get<%- camelize(originalPropertyName(property)) %>() ?: _rawLayer->getDefault<%- camelize(originalPropertyName(property)) %>();
 <% if (property.type == "enum") { -%>
     return MGLStyleValueTransformer<mbgl::style::<%- mbglType(property) %>, NSValue *, mbgl::style::<%- mbglType(property) %>, MGL<%- camelize(originalPropertyName(property)) %>>().toEnumStyleValue(propertyValue);

platform/darwin/src/MGLStyleLayer_Private.h

@@ -5,6 +5,25 @@
 
 #include <mbgl/style/layer.hpp>
 
+/**
+ Assert that the style layer is valid.
+
+ This macro should be used at the beginning of any public-facing instance method
+ of `MGLStyleLayer` and its subclasses. For private methods, an assertion is more appropriate.
+ */
+#define MGLAssertStyleLayerIsValid() \
+    do { \
+        if (!self.rawLayer) { \
+            [NSException raise:@"Invalid style layer" \
+                        format: \
+            @"-[MGLStyle removeLayer:] has been called " \
+            @"with this instance but another style layer instance was added with the same identifer. It is an " \
+            @"error to send any message to this layer since it cannot be recovered after removal due to the " \
+            @"identifer collision. Use unique identifiers for all layer instances including layers of " \
+            @"different types."]; \
+        } \
+    } while (NO);
+
 @class MGLMapView;
 
 @interface MGLStyleLayer (Private)

platform/darwin/src/MGLSymbolStyleLayer.mm

@@ -99,22 +99,30 @@ namespace mbgl {
 }
 - (NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     auto layerID = _rawLayer->getSourceLayer();
     return layerID.empty() ? nil : @(layerID.c_str());
 }
 
 - (void)setSourceLayerIdentifier:(NSString *)sourceLayerIdentifier
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setSourceLayer(sourceLayerIdentifier.UTF8String ?: "");
 }
 
 - (void)setPredicate:(NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     _rawLayer->setFilter(predicate.mgl_filter);
 }
 
 - (NSPredicate *)predicate
 {
+    MGLAssertStyleLayerIsValid();
+
     return [NSPredicate mgl_predicateWithFilter:_rawLayer->getFilter()];
 }
 #pragma mark -  Adding to and removing from a map view
@@ -136,352 +144,499 @@ namespace mbgl {
 
 - (void)removeFromMapView:(MGLMapView *)mapView
 {
+    _pendingLayer = nullptr;
+    _rawLayer = nullptr;
+
     auto removedLayer = mapView.mbglMap->removeLayer(self.identifier.UTF8String);
     if (!removedLayer) {
         return;
     }
-    _pendingLayer = std::move(reinterpret_cast<std::unique_ptr<mbgl::style::SymbolLayer> &>(removedLayer));
+
+    mbgl::style::SymbolLayer *layer = dynamic_cast<mbgl::style::SymbolLayer *>(removedLayer.get());
+    if (!layer) {
+        return;
+    }
+
+    removedLayer.release();
+
+    _pendingLayer = std::unique_ptr<mbgl::style::SymbolLayer>(layer);
     _rawLayer = _pendingLayer.get();
 }
 
 #pragma mark - Accessing the Layout Attributes
 
 - (void)setIconAllowOverlap:(MGLStyleValue<NSNumber *> *)iconAllowOverlap {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(iconAllowOverlap);
     _rawLayer->setIconAllowOverlap(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconAllowOverlap {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconAllowOverlap() ?: _rawLayer->getDefaultIconAllowOverlap();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconIgnorePlacement:(MGLStyleValue<NSNumber *> *)iconIgnorePlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(iconIgnorePlacement);
     _rawLayer->setIconIgnorePlacement(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconIgnorePlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconIgnorePlacement() ?: _rawLayer->getDefaultIconIgnorePlacement();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconImageName:(MGLStyleValue<NSString *> *)iconImageName {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::string, NSString *>().toPropertyValue(iconImageName);
     _rawLayer->setIconImage(mbglValue);
 }
 
 - (MGLStyleValue<NSString *> *)iconImageName {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconImage() ?: _rawLayer->getDefaultIconImage();
     return MGLStyleValueTransformer<std::string, NSString *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconKeepUpright:(MGLStyleValue<NSNumber *> *)iconKeepUpright {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(iconKeepUpright);
     _rawLayer->setIconKeepUpright(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconKeepUpright {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconKeepUpright() ?: _rawLayer->getDefaultIconKeepUpright();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconOffset:(MGLStyleValue<NSValue *> *)iconOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(iconOffset);
     _rawLayer->setIconOffset(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconOffset() ?: _rawLayer->getDefaultIconOffset();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconOptional:(MGLStyleValue<NSNumber *> *)iconOptional {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(iconOptional);
     _rawLayer->setIconOptional(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconOptional {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconOptional() ?: _rawLayer->getDefaultIconOptional();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconPadding:(MGLStyleValue<NSNumber *> *)iconPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconPadding);
     _rawLayer->setIconPadding(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconPadding() ?: _rawLayer->getDefaultIconPadding();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconRotate:(MGLStyleValue<NSNumber *> *)iconRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconRotate);
     _rawLayer->setIconRotate(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconRotate() ?: _rawLayer->getDefaultIconRotate();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconRotationAlignment:(MGLStyleValue<NSValue *> *)iconRotationAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLIconRotationAlignment>().toEnumPropertyValue(iconRotationAlignment);
     _rawLayer->setIconRotationAlignment(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconRotationAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconRotationAlignment() ?: _rawLayer->getDefaultIconRotationAlignment();
     return MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLIconRotationAlignment>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setIconSize:(MGLStyleValue<NSNumber *> *)iconSize {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconSize);
     _rawLayer->setIconSize(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconSize {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconSize() ?: _rawLayer->getDefaultIconSize();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconTextFit:(MGLStyleValue<NSValue *> *)iconTextFit {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::IconTextFitType, NSValue *, mbgl::style::IconTextFitType, MGLIconTextFit>().toEnumPropertyValue(iconTextFit);
     _rawLayer->setIconTextFit(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconTextFit {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconTextFit() ?: _rawLayer->getDefaultIconTextFit();
     return MGLStyleValueTransformer<mbgl::style::IconTextFitType, NSValue *, mbgl::style::IconTextFitType, MGLIconTextFit>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setIconTextFitPadding:(MGLStyleValue<NSValue *> *)iconTextFitPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 4>, NSValue *>().toPropertyValue(iconTextFitPadding);
     _rawLayer->setIconTextFitPadding(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconTextFitPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconTextFitPadding() ?: _rawLayer->getDefaultIconTextFitPadding();
     return MGLStyleValueTransformer<std::array<float, 4>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setSymbolAvoidEdges:(MGLStyleValue<NSNumber *> *)symbolAvoidEdges {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(symbolAvoidEdges);
     _rawLayer->setSymbolAvoidEdges(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)symbolAvoidEdges {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getSymbolAvoidEdges() ?: _rawLayer->getDefaultSymbolAvoidEdges();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setSymbolPlacement:(MGLStyleValue<NSValue *> *)symbolPlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::SymbolPlacementType, NSValue *, mbgl::style::SymbolPlacementType, MGLSymbolPlacement>().toEnumPropertyValue(symbolPlacement);
     _rawLayer->setSymbolPlacement(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)symbolPlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getSymbolPlacement() ?: _rawLayer->getDefaultSymbolPlacement();
     return MGLStyleValueTransformer<mbgl::style::SymbolPlacementType, NSValue *, mbgl::style::SymbolPlacementType, MGLSymbolPlacement>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setSymbolSpacing:(MGLStyleValue<NSNumber *> *)symbolSpacing {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(symbolSpacing);
     _rawLayer->setSymbolSpacing(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)symbolSpacing {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getSymbolSpacing() ?: _rawLayer->getDefaultSymbolSpacing();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextAllowOverlap:(MGLStyleValue<NSNumber *> *)textAllowOverlap {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(textAllowOverlap);
     _rawLayer->setTextAllowOverlap(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textAllowOverlap {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextAllowOverlap() ?: _rawLayer->getDefaultTextAllowOverlap();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextAnchor:(MGLStyleValue<NSValue *> *)textAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TextAnchorType, NSValue *, mbgl::style::TextAnchorType, MGLTextAnchor>().toEnumPropertyValue(textAnchor);
     _rawLayer->setTextAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextAnchor() ?: _rawLayer->getDefaultTextAnchor();
     return MGLStyleValueTransformer<mbgl::style::TextAnchorType, NSValue *, mbgl::style::TextAnchorType, MGLTextAnchor>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setTextField:(MGLStyleValue<NSString *> *)textField {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::string, NSString *>().toPropertyValue(textField);
     _rawLayer->setTextField(mbglValue);
 }
 
 - (MGLStyleValue<NSString *> *)textField {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextField() ?: _rawLayer->getDefaultTextField();
     return MGLStyleValueTransformer<std::string, NSString *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextFont:(MGLStyleValue<NSArray<NSString *> *> *)textFont {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::vector<std::string>, NSArray<NSString *> *, std::string>().toPropertyValue(textFont);
     _rawLayer->setTextFont(mbglValue);
 }
 
 - (MGLStyleValue<NSArray<NSString *> *> *)textFont {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextFont() ?: _rawLayer->getDefaultTextFont();
     return MGLStyleValueTransformer<std::vector<std::string>, NSArray<NSString *> *, std::string>().toStyleValue(propertyValue);
 }
 
 - (void)setTextIgnorePlacement:(MGLStyleValue<NSNumber *> *)textIgnorePlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(textIgnorePlacement);
     _rawLayer->setTextIgnorePlacement(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textIgnorePlacement {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextIgnorePlacement() ?: _rawLayer->getDefaultTextIgnorePlacement();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextJustify:(MGLStyleValue<NSValue *> *)textJustify {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TextJustifyType, NSValue *, mbgl::style::TextJustifyType, MGLTextJustify>().toEnumPropertyValue(textJustify);
     _rawLayer->setTextJustify(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textJustify {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextJustify() ?: _rawLayer->getDefaultTextJustify();
     return MGLStyleValueTransformer<mbgl::style::TextJustifyType, NSValue *, mbgl::style::TextJustifyType, MGLTextJustify>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setTextKeepUpright:(MGLStyleValue<NSNumber *> *)textKeepUpright {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(textKeepUpright);
     _rawLayer->setTextKeepUpright(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textKeepUpright {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextKeepUpright() ?: _rawLayer->getDefaultTextKeepUpright();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextLetterSpacing:(MGLStyleValue<NSNumber *> *)textLetterSpacing {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textLetterSpacing);
     _rawLayer->setTextLetterSpacing(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textLetterSpacing {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextLetterSpacing() ?: _rawLayer->getDefaultTextLetterSpacing();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextLineHeight:(MGLStyleValue<NSNumber *> *)textLineHeight {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textLineHeight);
     _rawLayer->setTextLineHeight(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textLineHeight {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextLineHeight() ?: _rawLayer->getDefaultTextLineHeight();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextMaxAngle:(MGLStyleValue<NSNumber *> *)textMaxAngle {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textMaxAngle);
     _rawLayer->setTextMaxAngle(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textMaxAngle {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextMaxAngle() ?: _rawLayer->getDefaultTextMaxAngle();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextMaxWidth:(MGLStyleValue<NSNumber *> *)textMaxWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textMaxWidth);
     _rawLayer->setTextMaxWidth(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textMaxWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextMaxWidth() ?: _rawLayer->getDefaultTextMaxWidth();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextOffset:(MGLStyleValue<NSValue *> *)textOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(textOffset);
     _rawLayer->setTextOffset(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textOffset {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextOffset() ?: _rawLayer->getDefaultTextOffset();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextOptional:(MGLStyleValue<NSNumber *> *)textOptional {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<bool, NSNumber *>().toPropertyValue(textOptional);
     _rawLayer->setTextOptional(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textOptional {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextOptional() ?: _rawLayer->getDefaultTextOptional();
     return MGLStyleValueTransformer<bool, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextPadding:(MGLStyleValue<NSNumber *> *)textPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textPadding);
     _rawLayer->setTextPadding(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textPadding {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextPadding() ?: _rawLayer->getDefaultTextPadding();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextPitchAlignment:(MGLStyleValue<NSValue *> *)textPitchAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLTextPitchAlignment>().toEnumPropertyValue(textPitchAlignment);
     _rawLayer->setTextPitchAlignment(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textPitchAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextPitchAlignment() ?: _rawLayer->getDefaultTextPitchAlignment();
     return MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLTextPitchAlignment>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setTextRotate:(MGLStyleValue<NSNumber *> *)textRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textRotate);
     _rawLayer->setTextRotate(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textRotate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextRotate() ?: _rawLayer->getDefaultTextRotate();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextRotationAlignment:(MGLStyleValue<NSValue *> *)textRotationAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLTextRotationAlignment>().toEnumPropertyValue(textRotationAlignment);
     _rawLayer->setTextRotationAlignment(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textRotationAlignment {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextRotationAlignment() ?: _rawLayer->getDefaultTextRotationAlignment();
     return MGLStyleValueTransformer<mbgl::style::AlignmentType, NSValue *, mbgl::style::AlignmentType, MGLTextRotationAlignment>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setTextSize:(MGLStyleValue<NSNumber *> *)textSize {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textSize);
     _rawLayer->setTextSize(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textSize {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextSize() ?: _rawLayer->getDefaultTextSize();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextTransform:(MGLStyleValue<NSValue *> *)textTransform {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TextTransformType, NSValue *, mbgl::style::TextTransformType, MGLTextTransform>().toEnumPropertyValue(textTransform);
     _rawLayer->setTextTransform(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textTransform {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextTransform() ?: _rawLayer->getDefaultTextTransform();
     return MGLStyleValueTransformer<mbgl::style::TextTransformType, NSValue *, mbgl::style::TextTransformType, MGLTextTransform>().toEnumStyleValue(propertyValue);
 }
@@ -489,141 +644,197 @@ namespace mbgl {
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setIconColor:(MGLStyleValue<MGLColor *> *)iconColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(iconColor);
     _rawLayer->setIconColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)iconColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconColor() ?: _rawLayer->getDefaultIconColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconHaloBlur:(MGLStyleValue<NSNumber *> *)iconHaloBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconHaloBlur);
     _rawLayer->setIconHaloBlur(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconHaloBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconHaloBlur() ?: _rawLayer->getDefaultIconHaloBlur();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconHaloColor:(MGLStyleValue<MGLColor *> *)iconHaloColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(iconHaloColor);
     _rawLayer->setIconHaloColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)iconHaloColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconHaloColor() ?: _rawLayer->getDefaultIconHaloColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconHaloWidth:(MGLStyleValue<NSNumber *> *)iconHaloWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconHaloWidth);
     _rawLayer->setIconHaloWidth(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconHaloWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconHaloWidth() ?: _rawLayer->getDefaultIconHaloWidth();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconOpacity:(MGLStyleValue<NSNumber *> *)iconOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(iconOpacity);
     _rawLayer->setIconOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)iconOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconOpacity() ?: _rawLayer->getDefaultIconOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconTranslate:(MGLStyleValue<NSValue *> *)iconTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(iconTranslate);
     _rawLayer->setIconTranslate(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconTranslate() ?: _rawLayer->getDefaultIconTranslate();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setIconTranslateAnchor:(MGLStyleValue<NSValue *> *)iconTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLIconTranslateAnchor>().toEnumPropertyValue(iconTranslateAnchor);
     _rawLayer->setIconTranslateAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)iconTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getIconTranslateAnchor() ?: _rawLayer->getDefaultIconTranslateAnchor();
     return MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLIconTranslateAnchor>().toEnumStyleValue(propertyValue);
 }
 
 - (void)setTextColor:(MGLStyleValue<MGLColor *> *)textColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(textColor);
     _rawLayer->setTextColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)textColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextColor() ?: _rawLayer->getDefaultTextColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextHaloBlur:(MGLStyleValue<NSNumber *> *)textHaloBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textHaloBlur);
     _rawLayer->setTextHaloBlur(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textHaloBlur {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextHaloBlur() ?: _rawLayer->getDefaultTextHaloBlur();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextHaloColor:(MGLStyleValue<MGLColor *> *)textHaloColor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toPropertyValue(textHaloColor);
     _rawLayer->setTextHaloColor(mbglValue);
 }
 
 - (MGLStyleValue<MGLColor *> *)textHaloColor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextHaloColor() ?: _rawLayer->getDefaultTextHaloColor();
     return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextHaloWidth:(MGLStyleValue<NSNumber *> *)textHaloWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textHaloWidth);
     _rawLayer->setTextHaloWidth(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textHaloWidth {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextHaloWidth() ?: _rawLayer->getDefaultTextHaloWidth();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextOpacity:(MGLStyleValue<NSNumber *> *)textOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toPropertyValue(textOpacity);
     _rawLayer->setTextOpacity(mbglValue);
 }
 
 - (MGLStyleValue<NSNumber *> *)textOpacity {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextOpacity() ?: _rawLayer->getDefaultTextOpacity();
     return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextTranslate:(MGLStyleValue<NSValue *> *)textTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toPropertyValue(textTranslate);
     _rawLayer->setTextTranslate(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textTranslate {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextTranslate() ?: _rawLayer->getDefaultTextTranslate();
     return MGLStyleValueTransformer<std::array<float, 2>, NSValue *>().toStyleValue(propertyValue);
 }
 
 - (void)setTextTranslateAnchor:(MGLStyleValue<NSValue *> *)textTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto mbglValue = MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLTextTranslateAnchor>().toEnumPropertyValue(textTranslateAnchor);
     _rawLayer->setTextTranslateAnchor(mbglValue);
 }
 
 - (MGLStyleValue<NSValue *> *)textTranslateAnchor {
+    MGLAssertStyleLayerIsValid();
+
     auto propertyValue = _rawLayer->getTextTranslateAnchor() ?: _rawLayer->getDefaultTextTranslateAnchor();
     return MGLStyleValueTransformer<mbgl::style::TranslateAnchorType, NSValue *, mbgl::style::TranslateAnchorType, MGLTextTranslateAnchor>().toEnumStyleValue(propertyValue);
 }