[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.

9 files changed, 507 insertions, 11 deletions

diff --git a/platform/darwin/src/MGLBackgroundStyleLayer.mm b/platform/darwin/src/MGLBackgroundStyleLayer.mm
index 59aa06910e..c8f8b39b3e 100644
--- a/platform/darwin/src/MGLBackgroundStyleLayer.mm
+++ b/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);
 }
diff --git a/platform/darwin/src/MGLCircleStyleLayer.mm b/platform/darwin/src/MGLCircleStyleLayer.mm
index 1c903ab008..7768ff66c9 100644
--- a/platform/darwin/src/MGLCircleStyleLayer.mm
+++ b/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);
 }
diff --git a/platform/darwin/src/MGLFillStyleLayer.mm b/platform/darwin/src/MGLFillStyleLayer.mm
index 6f9c68f21f..d1a96f7230 100644
--- a/platform/darwin/src/MGLFillStyleLayer.mm
+++ b/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);
 }
diff --git a/platform/darwin/src/MGLLineStyleLayer.mm b/platform/darwin/src/MGLLineStyleLayer.mm
index c37d1b6590..a7ed2fc100 100644
--- a/platform/darwin/src/MGLLineStyleLayer.mm
+++ b/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);
 }
diff --git a/platform/darwin/src/MGLRasterStyleLayer.mm b/platform/darwin/src/MGLRasterStyleLayer.mm
index cd1d135ff2..24dba21c71 100644
--- a/platform/darwin/src/MGLRasterStyleLayer.mm
+++ b/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);
 }
diff --git a/platform/darwin/src/MGLStyleLayer.mm b/platform/darwin/src/MGLStyleLayer.mm
index d1943cd467..6d9dabf25e 100644
--- a/platform/darwin/src/MGLStyleLayer.mm
+++ b/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();
 }
 
diff --git a/platform/darwin/src/MGLStyleLayer.mm.ejs b/platform/darwin/src/MGLStyleLayer.mm.ejs
index ae90b67d39..85a1af9970 100644
--- a/platform/darwin/src/MGLStyleLayer.mm.ejs
+++ b/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);
diff --git a/platform/darwin/src/MGLStyleLayer_Private.h b/platform/darwin/src/MGLStyleLayer_Private.h
index bfce452a4a..e723c8cf1b 100644
--- a/platform/darwin/src/MGLStyleLayer_Private.h
+++ b/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)
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.mm b/platform/darwin/src/MGLSymbolStyleLayer.mm
index 3e5834f7b0..29fe322181 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.mm
+++ b/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);
 }