cmake fixes (#212)

csrc/sparse.h

 #pragma once
 
-#include <torch/library.h>
+#include <torch/extension.h>
 
 #ifdef _WIN32
 #if defined(torchsparse_EXPORTS)
@@ -12,32 +12,49 @@
 #define SPARSE_API
 #endif
 
+#if (defined __cpp_inline_variables) || __cplusplus >= 201703L
+#define SPARSE_INLINE_VARIABLE inline
+#else
+#ifdef _MSC_VER
+#define SPARSE_INLINE_VARIABLE __declspec(selectany)
+#else
+#define SPARSE_INLINE_VARIABLE __attribute__((weak))
+#endif
+#endif
 
-SPARSE_API int64_t cuda_version();
+namespace sparse {
+SPARSE_API int64_t cuda_version() noexcept;
+
+namespace detail {
+SPARSE_INLINE_VARIABLE int64_t _cuda_version = cuda_version();
+} // namespace detail
+} // namespace sparse
 
 SPARSE_API torch::Tensor ind2ptr(torch::Tensor ind, int64_t M);
 SPARSE_API torch::Tensor ptr2ind(torch::Tensor ptr, int64_t E);
 
-SPARSE_API torch::Tensor partition(torch::Tensor rowptr, torch::Tensor col,
-                        torch::optional<torch::Tensor> optional_value,
-                        int64_t num_parts, bool recursive);
+SPARSE_API torch::Tensor
+partition(torch::Tensor rowptr, torch::Tensor col,
+          torch::optional<torch::Tensor> optional_value, int64_t num_parts,
+          bool recursive);
 
-SPARSE_API torch::Tensor partition2(torch::Tensor rowptr, torch::Tensor col,
+SPARSE_API torch::Tensor
+partition2(torch::Tensor rowptr, torch::Tensor col,
            torch::optional<torch::Tensor> optional_value,
            torch::optional<torch::Tensor> optional_node_weight,
            int64_t num_parts, bool recursive);
 
-SPARSE_API torch::Tensor mt_partition(torch::Tensor rowptr, torch::Tensor col,
+SPARSE_API torch::Tensor
+mt_partition(torch::Tensor rowptr, torch::Tensor col,
              torch::optional<torch::Tensor> optional_value,
              torch::optional<torch::Tensor> optional_node_weight,
-                           int64_t num_parts, bool recursive,
-                           int64_t num_workers);
+             int64_t num_parts, bool recursive, int64_t num_workers);
 
 SPARSE_API std::tuple<torch::Tensor, torch::Tensor> relabel(torch::Tensor col,
                                                             torch::Tensor idx);
 
-SPARSE_API std::tuple<torch::Tensor, torch::Tensor, torch::optional<torch::Tensor>,
-           torch::Tensor>
+SPARSE_API std::tuple<torch::Tensor, torch::Tensor,
+                      torch::optional<torch::Tensor>, torch::Tensor>
 relabel_one_hop(torch::Tensor rowptr, torch::Tensor col,
                 torch::optional<torch::Tensor> optional_value,
                 torch::Tensor idx, bool bipartite);
@@ -49,7 +66,8 @@ SPARSE_API std::tuple<torch::Tensor, torch::Tensor, torch::Tensor>
 subgraph(torch::Tensor idx, torch::Tensor rowptr, torch::Tensor row,
          torch::Tensor col);
 
-SPARSE_API std::tuple<torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor>
+SPARSE_API
+std::tuple<torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor>
 sample_adj(torch::Tensor rowptr, torch::Tensor col, torch::Tensor idx,
            int64_t num_neighbors, bool replace);
 
@@ -76,7 +94,8 @@ SPARSE_API std::tuple<torch::Tensor, torch::Tensor>
 spmm_max(torch::Tensor rowptr, torch::Tensor col,
          torch::optional<torch::Tensor> opt_value, torch::Tensor mat);
 
-SPARSE_API std::tuple<torch::Tensor, torch::Tensor, torch::optional<torch::Tensor>>
+SPARSE_API
+std::tuple<torch::Tensor, torch::Tensor, torch::optional<torch::Tensor>>
 spspmm_sum(torch::Tensor rowptrA, torch::Tensor colA,
            torch::optional<torch::Tensor> optional_valueA,
            torch::Tensor rowptrB, torch::Tensor colB,

csrc/version.cpp

 #ifdef WITH_PYTHON
 #include <Python.h>
 #endif
-#include <torch/script.h>
 #include "sparse.h"
+#include <torch/script.h>
 
 #ifdef WITH_CUDA
 #include <cuda.h>
@@ -18,13 +18,15 @@ PyMODINIT_FUNC PyInit__version_cpu(void) { return NULL; }
 #endif
 #endif
 
-SPARSE_API int64_t cuda_version() {
+namespace sparse {
+SPARSE_API int64_t cuda_version() noexcept {
 #ifdef WITH_CUDA
   return CUDA_VERSION;
 #else
   return -1;
 #endif
 }
+} // namespace sparse
 
-static auto registry =
-    torch::RegisterOperators().op("torch_sparse::cuda_version", &cuda_version);
+static auto registry = torch::RegisterOperators().op(
+    "torch_sparse::cuda_version", &sparse::cuda_version);