[BE] [3/N] Use nested namespaces (pytorch#110314)

Mostly in torch/csrc/jit/runtime and in `ATen/cuda/`

Pull Request resolved: pytorch#110314
Approved by: https://github.com/seemethere

Author: malfet

aten/src/ATen/CachedTensorUtils.cpp

@@ -3,8 +3,7 @@
 
 #include <c10/util/flat_hash_map.h>
 
-namespace at {
-namespace caching {
+namespace at::caching {
 
 
 using weakref_type = c10::weak_intrusive_ptr<TensorImpl, UndefinedTensorImpl>;
@@ -45,5 +44,4 @@ size_t adjusted_use_count(const at::Tensor& t) {
   return t.use_count() - (is_cached_tensor(t) ? 1 : 0);
 }
 
-}
-}
+} // namespace at::caching

aten/src/ATen/CachedTensorUtils.h

@@ -2,8 +2,7 @@
 
 #include <ATen/ATen.h>
 
-namespace at {
-namespace caching {
+namespace at::caching {
 
 // Some systems (just cudagraphs currently) will persist a static tensor output
 // whose TensorImpl does not change across iterations. For these tensors caching
@@ -22,5 +21,4 @@ TORCH_API void set_cached_tensors_enabled(bool enable);
 // count of tensors with hooks.
 TORCH_API size_t adjusted_use_count(const at::Tensor& t);
 
-} // namespace caching
-} // namespace at
+} // namespace at::caching

aten/src/ATen/EmptyTensor.cpp

@@ -6,8 +6,7 @@
 
 #include <limits>
 
-namespace at {
-namespace detail {
+namespace at::detail {
 namespace {
 c10::Allocator* GetCPUAllocatorMaybePinned(bool pin_memory) {
   if (pin_memory) {
@@ -441,4 +440,4 @@ TensorBase empty_strided_symint_meta(
       options.pinned_memory_opt());
 }
 
-}} // namespace at::detail
+} // namespace at::detail

aten/src/ATen/EmptyTensor.h

@@ -1,8 +1,7 @@
 #pragma once
 #include <ATen/core/TensorBase.h>
 
-namespace at {
-namespace detail {
+namespace at::detail {
 
 inline void check_size_nonnegative(ArrayRef<int64_t> size) {
   for (const auto& x : size) {
@@ -158,5 +157,4 @@ TORCH_API TensorBase empty_strided_symint_meta(
     SymIntArrayRef stride,
     const TensorOptions& options);
 
-} // namespace detail
-} // namespace at
+} // namespace at::detail

aten/src/ATen/ExpandUtils.cpp

@@ -9,7 +9,7 @@ namespace internal {
 TensorBase expand_slow_path(const TensorBase &self, IntArrayRef size) {
   return OptionalTensorRef(self)->expand(size);
 }
-}
+} // namespace internal
 
 namespace {
 // NOTE: are_expandable did a similar check, please keep them sync if change is needed

aten/src/ATen/FuncTorchTLS.cpp

@@ -1,6 +1,6 @@
 #include <ATen/FuncTorchTLS.h>
 
-namespace at { namespace functorch {
+namespace at::functorch {
 
 namespace {
 
@@ -28,4 +28,4 @@ std::unique_ptr<FuncTorchTLSBase>& functorchTLSAccessor() {
 }
 
 
-}}
+} // namespace at::functorch

aten/src/ATen/FuncTorchTLS.h

@@ -3,8 +3,7 @@
 #include <c10/macros/Macros.h>
 #include <memory>
 
-namespace at {
-namespace functorch {
+namespace at::functorch {
 
 // NOTE [functorch TLS in pytorch/pytorch]
 //
@@ -44,5 +43,4 @@ TORCH_API void setFuncTorchTLS(
 // get a mutable reference to the functorch tls
 TORCH_API std::unique_ptr<FuncTorchTLSBase>& functorchTLSAccessor();
 
-} // namespace functorch
-} // namespace at
+} // namespace at::functorch

aten/src/ATen/FunctionalInverses.cpp

@@ -6,8 +6,7 @@
 #include <ATen/WrapDimUtilsMulti.h>
 
 #include <utility>
-namespace at {
-namespace functionalization {
+namespace at::functionalization {
 
 // This logic is similar to autograd code for view backwards calls.
 // We can't easily share it though, because (eventually) these functions
@@ -348,5 +347,4 @@ Tensor FunctionalInverses::alias_copy_inverse(const Tensor& base, const Tensor&
     }
 }
 
-} // functionalization
-} // at
+} // namespace at::functionalization

aten/src/ATen/FunctionalStorageImpl.cpp

@@ -6,8 +6,7 @@
 #include <c10/util/Exception.h>
 #include <vector>
 
-namespace at {
-namespace functionalization {
+namespace at::functionalization {
 
 ViewMeta ViewMeta::to_out_idx(int64_t out_idx) {
   if (out_idx == this->out_index) return *this;
@@ -122,5 +121,4 @@ bool FunctionalStorageImpl::apply_updates() {
   return any_updates;
 }
 
-} // namespace functionalization
-} // namespace at
+} // namespace at::functionalization

aten/src/ATen/FunctionalStorageImpl.h

@@ -2,8 +2,7 @@
 
 #include <ATen/Tensor.h>
 
-namespace at {
-namespace functionalization {
+namespace at::functionalization {
 
 // See Note [Functionalization Pass In Core]
 
@@ -117,5 +116,4 @@ struct TORCH_API FunctionalStorageImpl : public c10::StorageImpl {
   bool frozen_ = false;
 };
 
-} // namespace functionalization
-} // namespace at
+} // namespace at::functionalization