Made the tensor contain a cudnn tensor descriptor and also added a few other

minor refinements.

dlib/dnn/cublas.h

@@ -24,8 +24,12 @@ namespace dlib
         class cublas_context
         {
         public:
+            // not copyable
             cublas_context(const cublas_context&) = delete;
             cublas_context& operator=(const cublas_context&) = delete;
+            // but is movable
+            cublas_context(const cublas_context&&) = default;
+            cublas_context& operator=(const cublas_context&&) = default;
 
             cublas_context()
             {
@@ -36,6 +40,10 @@ namespace dlib
             {
                 // TODO
             }
+
+            const void* get_handle (
+            ) const { return handle; }
+
         private:
 
             void* handle;

dlib/dnn/cuda.h

@@ -108,8 +108,12 @@ namespace dlib
             !*/
         public:
 
+            // not copyable
             dropout(const dropout&) = delete;
             dropout& operator=(const dropout&) = delete;
+            // but is movable
+            dropout(const dropout&&) = default;
+            dropout& operator=(const dropout&&) = default;
 
             dropout(float drop_rate = 0.5);
             dropout(float drop_rate, int seed);

dlib/dnn/cudnn.h

@@ -9,6 +9,9 @@
 
 namespace dlib
 {
+    class tensor;
+    class resizable_tensor;
+
     namespace cuda 
     {
 
@@ -24,8 +27,12 @@ namespace dlib
         class cudnn_context
         {
         public:
+            // not copyable 
             cudnn_context(const cudnn_context&) = delete;
             cudnn_context& operator=(const cudnn_context&) = delete;
+            // but is movable
+            cudnn_context(cudnn_context&&) = default;
+            cudnn_context& operator=(cudnn_context&&) = default;
 
             cudnn_context()
             {
@@ -38,6 +45,10 @@ namespace dlib
                 // TODO
                 // cudnnDestroy()
             }
+
+            const void* get_handle (
+            ) const { return handle; }
+
         private:
 
             void* handle;
@@ -53,8 +64,12 @@ namespace dlib
             !*/
 
         public:
+            // not copyable
             tensor_descriptor(const tensor_descriptor&) = delete;
             tensor_descriptor& operator=(const tensor_descriptor&) = delete;
+            // but is movable
+            tensor_descriptor(tensor_descriptor&&) = default;
+            tensor_descriptor& operator=(tensor_descriptor&&) = default;
 
             tensor_descriptor()
             {
@@ -69,6 +84,23 @@ namespace dlib
                 // cudnnDestroyTensorDescriptor()
             }
 
+            void set_size(
+                int n, 
+                int nr, 
+                int nc, 
+                int k
+            );
+
+            void get_size (
+                int& n, 
+                int& nr, 
+                int& nc, 
+                int& k
+            ) const;
+
+            const void* get_handle (
+            ) const { return handle; }
+
         private:
 
             void* handle;

dlib/dnn/tensor.h

@@ -6,6 +6,7 @@
 #include <memory>
 #include <cstring>
 #include "../matrix.h"
+#include "cudnn.h"
 
 namespace dlib
 {
@@ -246,6 +247,11 @@ namespace dlib
         }
 
 
+#ifdef DLIB_USE_CUDA
+        const cuda::tensor_descriptor& get_cudnn_tensor_descriptor (
+        ) const { return cudnn_descriptor; }
+#endif
+
 
 
     protected:
@@ -258,6 +264,10 @@ namespace dlib
             m_k  = item.m_k;
             data.set_size(item.data.size());
             std::memcpy(data.host(), item.data.host(), data.size()*sizeof(float));
+#ifdef DLIB_USE_CUDA
+            cudnn_descriptor.set_size(m_n,m_nr,m_nc,m_k);
+
+#endif
             return *this;
         }
 
@@ -277,6 +287,9 @@ namespace dlib
         long m_nc;
         long m_k;
         gpu_data data;
+#ifdef DLIB_USE_CUDA
+        cuda::tensor_descriptor cudnn_descriptor;
+#endif 
     };
 
     tensor::~tensor()
@@ -431,6 +444,10 @@ namespace dlib
             m_nc = nc_;
             m_k = k_;
             data.set_size(m_n*m_nr*m_nc*m_k);
+#ifdef DLIB_USE_CUDA
+            cudnn_descriptor.set_size(m_n,m_nr,m_nc,m_k);
+
+#endif
         }
     };