Replace 'struct Tensor' with 'class Tensor'. (pytorch#12034)

Summary:
Pull Request resolved: pytorch#12034

We need ATen and Caffe2 to line up, and the rule is
that if you have any private/protected members, you
should declare it as a class.  Class we go.

(There are some other obvious candidates for this treatment,
but I've kept this patch just to Tensor)

Reviewed By: gchanan, mingzhe09088

Differential Revision: D10024467

fbshipit-source-id: 17cfe2741ba9c3f56cb87d6f5d1afd3c61a8e4fe

Author: ezyang

aten/src/ATen/Context.h

@@ -22,7 +22,7 @@
 
 namespace at {
 
-struct Tensor;
+class Tensor;
 
 class CAFFE2_API Context {
  public:

aten/src/ATen/core/Scalar.h

@@ -12,7 +12,7 @@
 
 namespace at {
 
-struct Tensor;
+class Tensor;
 
 class CAFFE2_API Scalar {
  public:

aten/src/ATen/core/ScalarType.h

@@ -188,7 +188,7 @@ static inline ScalarType promoteTypes(ScalarType a, ScalarType b) {
   return _promoteTypesLookup[static_cast<int>(a)][static_cast<int>(b)];
 }
 
-struct Tensor;
+class Tensor;
 typedef ArrayRef<int64_t> IntList;
 typedef ArrayRef<Tensor> TensorList;
 

aten/src/ATen/core/SparseTensorRef.h

@@ -2,7 +2,7 @@
 
 namespace at {
 
-struct Tensor;
+class Tensor;
 struct SparseTensorRef {
   explicit SparseTensorRef(const Tensor& t): tref(t) {}
   const Tensor& tref;

aten/src/ATen/core/Tensor.h

@@ -15,7 +15,7 @@
 namespace at {
 struct Generator;
 struct Type;
-struct Tensor;
+class Tensor;
 struct TensorOptions;
 } // namespace at
 
@@ -37,7 +37,8 @@ namespace at {
 //
 // Note that Tensor can also be NULL, i.e. it is not associated with any underlying TensorImpl, and
 // special care must be taken to handle this.
-struct CAFFE2_API Tensor {
+class CAFFE2_API Tensor {
+public:
   Tensor(){};
   Tensor(c10::intrusive_ptr<TensorImpl, UndefinedTensorImpl> tensor_impl)
       : impl_(std::move(tensor_impl)) {

aten/src/ATen/core/TensorImpl.h

@@ -16,7 +16,7 @@ namespace at {
 class Scalar;
 struct Type;
 struct Storage;
-struct Tensor;
+class Tensor;
 } // namespace at
 
 namespace at {

aten/src/ATen/core/Type.h

@@ -33,7 +33,7 @@ class Context;
 struct Allocator;
 struct Generator;
 struct Storage;
-struct Tensor;
+class Tensor;
 
 static inline void noop_deleter(void*) {}
 

aten/src/ATen/templates/NativeFunctions.h

@@ -16,7 +16,7 @@
 namespace at {
 struct Generator;
 class Scalar;
-struct Tensor;
+class Tensor;
 struct Type;
 } // namespace at
 

aten/src/ATen/templates/Tensor.h

@@ -15,7 +15,7 @@
 namespace at {
 struct Generator;
 struct Type;
-struct Tensor;
+class Tensor;
 struct TensorOptions;
 } // namespace at
 
@@ -37,7 +37,8 @@ namespace at {
 //
 // Note that Tensor can also be NULL, i.e. it is not associated with any underlying TensorImpl, and
 // special care must be taken to handle this.
-struct CAFFE2_API Tensor {
+class CAFFE2_API Tensor {
+public:
   Tensor(){};
   Tensor(c10::intrusive_ptr<TensorImpl, UndefinedTensorImpl> tensor_impl)
       : impl_(std::move(tensor_impl)) {

aten/src/ATen/templates/Type.h

@@ -33,7 +33,7 @@ class Context;
 struct Allocator;
 struct Generator;
 struct Storage;
-struct Tensor;
+class Tensor;
 
 static inline void noop_deleter(void*) {}