Remove dataP in XTensor and use const_cast to modify the const data.

source/tensor/XTensor.cpp

@@ -87,7 +87,6 @@ int MakeTensorID()
 XTensor::XTensor()
 {
     Init();
-    SetDataPointer();
 
     id = MakeTensorID();
     isDefaultDType = true;
@@ -100,7 +99,6 @@ XTensor::XTensor()
 XTensor::XTensor(const XTensor* reference)
 {
     Init();
-    SetDataPointer();
     id = MakeTensorID();
 
     InitTensorV2(this, reference);
@@ -117,7 +115,6 @@ XTensor::XTensor(const int myOrder, int myDevID, XMem* myMem)
     CheckNTErrors((myOrder >= 0), "Illegal tensor order!");
 
     Init();
-    SetDataPointer();
 
     id = MakeTensorID();
     order = myOrder;
@@ -138,7 +135,6 @@ XTensor::XTensor(const int myOrder, const int * myDimSize, const TENSOR_DATA_TYP
                  const float myDenseRatio, int myDevID, XMem * myMem)
 {
     Init();
-    SetDataPointer();
 
     id = MakeTensorID();
     order = myOrder;
@@ -153,7 +149,6 @@ XTensor::XTensor(const int myOrder, const int * myDimSize, const TENSOR_DATA_TYP
 XTensor::XTensor(const XTensor& reference)
 {
     Init();
-    SetDataPointer();
     id = MakeTensorID();
     ShallowCopy(reference);
     data = NULL;
@@ -164,13 +159,7 @@ XTensor::XTensor(const XTensor& reference)
         mem = reference.mem;
         data = reference.data;
         signature = reference.signature;
-        
-        /* what we really want to do is "reference.data = NULL;"
-           As "reference" is constant, we cannot reset "reference.data"
-           here. So we save the ADDRESS of "reference.data" in
-           "reference.dataP", and do this work by updating "*reference.dataP".
-           This is VERY tricky and there might be better solutions :) */
-        *reference.dataP = NULL;
+        const_cast<XTensor&>(reference).data = NULL;
     }
     else{
         devID = reference.devID;
@@ -196,7 +185,6 @@ XTensor::XTensor(const XTensor& reference)
 XTensor::XTensor(const XTensor&& reference)
 {
     Init();
-    SetDataPointer();
     id = MakeTensorID();
     ShallowCopy(reference);
     data = NULL;
@@ -206,13 +194,7 @@ XTensor::XTensor(const XTensor&& reference)
     mem = reference.mem;
     data = reference.data;
     signature = reference.signature;
-        
-    /* what we really want to do is "reference.data = NULL;"
-       As "reference" is constant, we cannot reset "reference.data"
-       here. So we save the ADDRESS of "reference.data" in
-       "reference.dataP", and do this work by updating "*reference.dataP".
-       This is VERY tricky and there might be better solutions :) */
-    *reference.dataP = NULL;
+    const_cast<XTensor&>(reference).data = NULL;
 
     if (reference.enableGrad) {
         XLink::Replace(&reference, this);
@@ -268,7 +250,6 @@ void XTensor::Init()
     signature = 0;
     data = NULL;
     dataHost = NULL;
-    dataP = NULL;
     devID = -1;
     order = -1;
     memset(dimSize, 0, sizeof(int) * MAX_TENSOR_DIM_NUM);
@@ -452,13 +433,7 @@ XTensor& XTensor::operator= (const XTensor&& tensor)
     mem = tensor.mem;
     data = tensor.data;
     signature = tensor.signature;
-        
-    /* what we really want to do is "reference.data = NULL;"
-       As "reference" is constant, we cannot reset "reference.data"
-       here. So we save the ADDRESS of "reference.data" in
-       "reference.dataP", and do this work by updating "*reference.dataP".
-       This is VERY tricky and there might be better solutions :) */
-    *tensor.dataP = NULL;
+    const_cast<XTensor&>(tensor).data = NULL;
 
     if (enableGrad) {
         XLink::Copy(&tensor, this);
@@ -909,12 +884,6 @@ void XTensor::SetDataBatchedWithValues(MTYPE* offsets, void* values, int num)
     _SetDataWithOffsetAndValue(this, offsets, values, num);
 }
 
-/* set the pointer to "data" */
-void XTensor::SetDataPointer()
-{
-    dataP = &data;
-}
-
 /* 
 get the value of a cell with the index 
 >> index - index of each dimension

source/tensor/XTensor.h

@@ -82,10 +82,6 @@ public:
        when the tensor is operated on GPUs */
     void * dataHost;
 
-    /* a pointer to data (i.e., a pointer to the address of "data".
-       This is for reset "data" when XTensor is used as a const variable. */
-    void ** dataP;
-
     /* 
     device id 
     <0:  CPU memory
@@ -331,9 +327,6 @@ public:
     /* set tensor items with an array of values */
     void SetDataBatchedWithValues(MTYPE * offsets, void * values, int num);
 
-    /* set the pointer to "data" */
-    void SetDataPointer();
-
     /* get the value of a cell with the index */
     DTYPE Get(int index[], int size = -1) const;