1. fix miss type value.

2. fix type conver performance bug

src/TensorFlowNET.Core/Tensors/TF_DataType.cs

@@ -35,6 +35,25 @@
         DtFloatRef = 101, // DT_FLOAT_REF
         DtDoubleRef = 102, // DT_DOUBLE_REF
         DtInt32Ref = 103, // DT_INT32_REF
-        DtInt64Ref = 109 // DT_INT64_REF
+        DtUint8Ref = 104,
+        DtInt16Ref = 105,
+        DtInt8Ref = 106,
+        DtStringRef = 107,
+        DtComplex64Ref = 108,
+        DtInt64Ref = 109, // DT_INT64_REF
+        DtBoolRef = 110,
+        DtQint8Ref = 111,
+        DtQuint8Ref = 112,
+        DtQint32Ref = 113,
+        DtBfloat16Ref = 114,
+        DtQint16Ref = 115,
+        DtQuint16Ref = 116,
+        DtUint16Ref = 117,
+        DtComplex128Ref = 118,
+        DtHalfRef = 119,
+        DtResourceRef = 120,
+        DtVariantRef = 121,
+        DtUint32Ref = 122,
+        DtUint64Ref = 123,
     }
 }

src/TensorFlowNET.Core/Tensors/dtypes.cs

@@ -46,7 +46,7 @@ namespace Tensorflow
         /// <returns><see cref="System.Type"/> equivalent to <paramref name="type"/>, if none exists, returns null.</returns>
         public static Type as_numpy_dtype(this TF_DataType type)
         {
-            switch (type)
+            switch (type.as_base_dtype())
             {
                 case TF_DataType.TF_BOOL:
                     return typeof(bool);
@@ -182,14 +182,12 @@ namespace Tensorflow
 
         public static DataType as_datatype_enum(this TF_DataType type)
         {
-            return Enum.TryParse(((int) type).ToString(), out DataType dtype) ? dtype : DataType.DtInvalid;
+            return (DataType)type;
         }
 
         public static TF_DataType as_base_dtype(this TF_DataType type)
         {
-            return (int)type > 100 ?
-                (TF_DataType)Enum.Parse(typeof(TF_DataType), ((int)type - 100).ToString()) :
-                type;
+            return (int)type > 100 ? (TF_DataType)((int)type - 100) : type;
         }
 
         public static int name(this TF_DataType type)
@@ -204,21 +202,17 @@ namespace Tensorflow
 
         public static DataType as_base_dtype(this DataType type)
         {
-            return (int)type > 100 ?
-                (DataType)Enum.Parse(typeof(DataType), ((int)type - 100).ToString()) :
-                type;
+            return (int)type > 100 ? (DataType)((int)type - 100) : type;
         }
 
         public static TF_DataType as_tf_dtype(this DataType type)
         {
-            return Enum.TryParse(((int) type).ToString(), out TF_DataType dtype) ? dtype : TF_DataType.DtInvalid;
+            return (TF_DataType)type;
         }
 
         public static TF_DataType as_ref(this TF_DataType type)
         {
-            return (int)type < 100 ?
-                (TF_DataType)Enum.Parse(typeof(TF_DataType), ((int)type + 100).ToString()) :
-                type;
+            return (int)type < 100 ? (TF_DataType)((int)type + 100) : type;
         }
 
         public static long max(this TF_DataType type)