allow Map to unify from all of its target types

std/Map.hx

@@ -20,25 +20,35 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+ import haxe.ds.StringMap;
+ import haxe.ds.IntMap;
+ import haxe.ds.HashMap;
+ import haxe.ds.ObjectMap;
+
 @:multiType
 abstract Map<K,V>(IMap < K, V > ) {
 	public function new();
 
-	@:to static inline function toHash(t:IMap < String, V > ):haxe.ds.StringMap<V> {
-		return new haxe.ds.StringMap<V>();
+	@:to static inline function toHash(t:IMap < String, V > ):StringMap<V> {
+		return new StringMap<V>();
 	}
 
-	@:to static inline function toIntHash(t:IMap < Int, V > ):haxe.ds.IntMap<V> {
-		return new haxe.ds.IntMap<V>();
+	@:to static inline function toIntHash(t:IMap < Int, V > ):IntMap<V> {
+		return new IntMap<V>();
 	}
 
-	@:to static inline function toHashMap<K:{ function hashCode():Int; }>(t:IMap < K, V >):haxe.ds.HashMap<K,V> {
-		return new haxe.ds.HashMap<K, V>();
+	@:to static inline function toHashMap<K:Hashable>(t:IMap < K, V >):HashMap<K,V> {
+		return new HashMap<K, V>();
 	}
 	
-	@:to static inline function toObjectMap<K:{ }>(t:IMap < K, V >):haxe.ds.ObjectMap<K,V> {
-		return new haxe.ds.ObjectMap<K, V>();
+	@:to static inline function toObjectMap<K:{ }>(t:IMap < K, V >):ObjectMap<K,V> {
+		return new ObjectMap<K, V>();
 	}
+	
+	@:from static inline function fromStringMap<V>(map:StringMap<V>):Map<String,V> return map
+	@:from static inline function fromIntMap<V>(map:IntMap<V>):Map<Int,V> return map
+	@:from static inline function fromHashMap<K:Hashable,V>(map:HashMap<K,V>):Map<K,V> return map
+	@:from static inline function fromObjectMap<K:{},V>(map:ObjectMap<K,V>):Map<K,V> return map
 
 	public inline function set(k:K, v:V) this.set(k, v)
 	public inline function get(k:K) return this.get(k)
@@ -56,3 +66,7 @@ private typedef IMap < K, V > = {
 	public function keys():Iterator<K>;
 	public function iterator():Iterator<V>;
 }
+
+private typedef Hashable = {
+	function hashCode():Int;
+}