Generic abstract database class

include/aidge/data/Database.hpp

@@ -2,40 +2,38 @@
 #define Database_H_
 
 #include <cstring>
+#include <memory>
+#include <vector>
+#include <tuple>
 
 #include "aidge/data/Tensor.hpp"
 
-namespace Aidge{
+namespace Aidge {
 
 /**
- * @brief Database. An abstract class representing a database. All databases should inherit from this class. All subclasses should overwrite :cpp:function:`Database::get_item` to fetch data from a given index.
- * @todo Make the dataset generic. Always ground truth.
+ * @brief Database. An abstract class representing a map from a key to data. All databases should inherit from this class. All subclasses should overwrite :cpp:function:`Database::getItem` to fetch data from a given index.
  */
 class Database {
 
 public:
-
+    Database() = default;
     virtual ~Database() = default; 
 
     /**
-     * @brief Fetch a data sample and its corresponding ground_truth 
-     * @param index index of the pair (```data```, ```ground truth```) to fetch from the database
-     * @return A pair of pointers to the data (first) and its corresping ground truth (second)
+     * @brief Fetch an item of the database. 
+     * @param index index of the item.
+     * @return vector of data mapped to index.
      */
-    virtual std::pair<std::shared_ptr<Tensor>,std::shared_ptr<Tensor>> get_item(unsigned int index) = 0;
+    virtual std::vector<std::shared_ptr<Tensor>> getItem(std::size_t index) = 0;
 
-    /** 
-     * @return The number of data samples in the database.
+    /**
+     * @brief Get the number of items in the database
+     * 
+     * @return std::size_t 
      */
-    virtual unsigned int get_len() = 0;
-
-protected:
-    
-    std::vector<std::shared_ptr<Tensor>> mData;
-    std::vector<std::shared_ptr<Tensor>> mLabel;
+    virtual std::size_t getLen() = 0;
 
 };
-
-}
+} // namespace Aidge
 
 #endif /* Database_H_ */
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