[ios, macos] Designated initializers

Added designated initializers to MGLStyleValue and friends. Restored custom equality and descriptions to MGLStyleFunction. Raise an exception if an unrecognized subclass of MGLStyleValue or MGLStyleValue itself is passed into a style attribute property.

1 files changed, 5 insertions, 2 deletions

diff --git a/platform/darwin/src/MGLStyleValue.h b/platform/darwin/src/MGLStyleValue.h
index 1f19a5e028..010a0d68cb 100644
--- a/platform/darwin/src/MGLStyleValue.h
+++ b/platform/darwin/src/MGLStyleValue.h
@@ -13,7 +13,9 @@
 
 + (instancetype)valueWithRawValue:(T)rawValue;
 
-- (instancetype)initWithRawValue:(T)rawValue;
+- (instancetype)init NS_UNAVAILABLE;
+
+- (instancetype)initWithRawValue:(T)rawValue NS_DESIGNATED_INITIALIZER;
 
 @property (nonatomic) T rawValue;
 
@@ -22,9 +24,10 @@
 @interface MGLStyleFunction<T> : MGLStyleValue
 
 + (instancetype)functionWithBase:(CGFloat)base stops:(NSDictionary<NSNumber *, MGLStyleValue<T> *> *)stops;
+
 + (instancetype)functionWithStops:(NSDictionary<NSNumber *, MGLStyleValue<T> *> *)stops;
 
-- (instancetype)initWithBase:(CGFloat)base stops:(NSDictionary<NSNumber *, MGLStyleValue<T> *> *)stops;
+- (instancetype)initWithBase:(CGFloat)base stops:(NSDictionary<NSNumber *, MGLStyleValue<T> *> *)stops NS_DESIGNATED_INITIALIZER;
 
 @property (nonatomic) CGFloat base;
 @property (nonatomic, copy) NSDictionary<NSNumber *, MGLStyleValue<T> *> *stops;