Refactor Backend and Layer interfaces

include/layer.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <vector>
+
+#include "shape.hpp"
+#include "tensor.hpp"
+
+#define CUDANET_SAME_PADDING(inputSize, kernelSize, stride) \
+    ((stride - 1) * inputSize - stride + kernelSize) / 2;
+
+
+namespace CUDANet {
+
+/**
+ * @brief Basic Sequential Layer
+ *
+ */
+class Layer {
+  public:
+
+    virtual ~Layer(){};
+
+    virtual CUDANet::Tensor& forward(CUDANet::Tensor &input) = 0;
+    
+    virtual CUDANet::Shape input_shape() = 0;
+
+    virtual CUDANet::Shape output_shape() = 0;
+
+    virtual int input_size() = 0;
+
+    virtual int output_size() = 0;
+
+    virtual void set_weights(CUDANet::Tensor &input) = 0;
+
+    virtual CUDANet::Tensor& get_weights() = 0;
+
+    virtual void set_biases(CUDANet::Tensor &input) = 0;
+
+    virtual CUDANet::Tensor& get_biases() = 0;
+};
+
+}  // namespace CUDANet::Layers