Migrate avg pooling

include/layers/avg_pooling.hpp

@@ -0,0 +1,78 @@
+#ifndef CUDANET_AVG_POOLING_H
+#define CUDANET_AVG_POOLING_H
+
+#include "activation.hpp"
+#include "layer.hpp"
+
+namespace CUDANet::Layers {
+
+class AvgPooling2d : public SequentialLayer, public TwoDLayer {
+  public:
+    AvgPooling2d(
+        shape2d        inputSize,
+        int            nChannels,
+        shape2d        poolingSize,
+        shape2d        stride,
+        shape2d        padding,
+        ActivationType activationType
+    );
+    ~AvgPooling2d();
+
+    float* forward(const float* input);
+
+    /**
+     * @brief Get output size
+     *
+     * @return int output size
+     */
+    int getOutputSize();
+
+    /**
+     * @brief Get input size
+     *
+     * @return int input size
+     */
+    int getInputSize();
+
+    shape2d getOutputDims();
+
+  protected:
+    shape2d inputSize;
+    int     nChannels;
+    shape2d poolingSize;
+    shape2d stride;
+    shape2d padding;
+
+    shape2d outputSize;
+
+    Activation* activation;
+
+    float* forwardCPU(const float* input);
+
+#ifdef USE_CUDA
+    float* d_output;
+    float* forwardCUDA(const float* d_input);
+
+    void initCUDA();
+    void delCUDA();
+#endif
+};
+
+class AdaptiveAvgPooling2d : public AvgPooling2d {
+  public:
+    AdaptiveAvgPooling2d(
+        shape2d        inputShape,
+        int            nChannels,
+        shape2d        outputShape,
+        ActivationType activationType
+    );
+
+  private:
+#ifdef USE_CUDA
+    void initCUDA();
+#endif
+};
+
+}  // namespace CUDANet::Layers
+
+#endif  // CUDANET_AVG_POOLING_H