[darwin] Make -[MGLForegroundStyleLayer sourceIdentifier] abstract

It's already overridden by concrete subclasses, and by making it abstract we enable the removal of the private MGLForegroundStyleLayer category.

1 files changed, 4 insertions, 15 deletions

diff --git a/platform/darwin/src/MGLForegroundStyleLayer.mm b/platform/darwin/src/MGLForegroundStyleLayer.mm
index 6926dfac1f..6888f89b92 100644
--- a/platform/darwin/src/MGLForegroundStyleLayer.mm
+++ b/platform/darwin/src/MGLForegroundStyleLayer.mm
@@ -1,22 +1,11 @@
 #import "MGLForegroundStyleLayer.h"
-#import "MGLForegroundStyleLayer_Private.h"
-#import "MGLStyleLayer_Private.h"
-#import "MGLSource.h"
 
 @implementation MGLForegroundStyleLayer
 
-- (instancetype)initWithRawLayer:(mbgl::style::Layer *)rawLayer source:(MGLSource *)source {
-    if (self = [super initWithRawLayer:rawLayer]) {
-        _sourceIdentifier = source.identifier;
-    }
-    return self;
-}
-
-- (instancetype)initWithPendingLayer:(std::unique_ptr<mbgl::style::Layer>)pendingLayer source:(MGLSource *)source {
-    if (self = [super initWithPendingLayer:std::move(pendingLayer)]) {
-        _sourceIdentifier = source.identifier;
-    }
-    return self;
+- (NSString *)sourceIdentifier {
+    [NSException raise:@"MGLAbstractClassException"
+                format:@"MGLForegroundStyleLayer is an abstract class"];
+    return nil;
 }
 
 - (NSString *)description {