[Add] Scalar constructor for Tensor and int8 support

include/aidge/backend/cpu/data/TensorImpl.hpp

@@ -185,6 +185,8 @@ static Registrar<Tensor> registrarTensorImpl_cpu_Float16(
         {"cpu", DataType::Float16}, Aidge::TensorImpl_cpu<half_float::half>::create);
 static Registrar<Tensor> registrarTensorImpl_cpu_Int32(
         {"cpu", DataType::Int32}, Aidge::TensorImpl_cpu<int>::create);
+static Registrar<Tensor> registrarTensorImpl_cpu_Int8(
+        {"cpu", DataType::Int8}, Aidge::TensorImpl_cpu<std::int8_t>::create);
 static Registrar<Tensor> registrarTensorImpl_cpu_Int64(
         {"cpu", DataType::Int64}, Aidge::TensorImpl_cpu<long>::create);
 }  // namespace

include/aidge/data/Tensor.hpp

@@ -17,6 +17,7 @@
 #include <memory>
 #include <numeric>   // std::accumulate
 #include <string>
+#include <type_traits>  // std::is_arithmetic
 #include <vector>
 
 #include "aidge/backend/TensorImpl.hpp"
@@ -63,7 +64,7 @@ class Tensor : public Data,
      * @brief Construct a new Tensor object from another one (shallow copy).
      * Data memory is not copied, but shared between the new Tensor and the
      * initial one.
-     * 
+     *
      * @param otherTensor
      */
     Tensor(const Tensor&)            = default;
@@ -85,6 +86,17 @@ class Tensor : public Data,
         return newTensor;
     }
 
+    template<typename T,
+            typename VT = std::enable_if_t<std::is_arithmetic<T>::value, std::decay_t<T>>>
+    Tensor(T val)
+        : Data(Type),
+          mDataType(NativeType<VT>::type),
+          mDims({}), mStrides({1}),
+          mImpl(Registrar<Tensor>::create({"cpu", NativeType<VT>::type})(0, 1)),
+          mSize(1) {
+        *static_cast<VT*>(mImpl->rawPtr()) = static_cast<VT>(val);
+    }
+
     /**
      * @brief Construct a new Tensor object from the 1-dimension Array helper.
      * @tparam T datatype
@@ -306,7 +318,7 @@ class Tensor : public Data,
 
     /**
      * @brief Set the Impl object
-     * 
+     *
      * @param impl New impl shared pointer
      * @param implOffset Storage offset in this new impl for this Tensor
      */
@@ -631,7 +643,7 @@ class Tensor : public Data,
      * tensor is returned.
      * It current tensor was contiguous, the returned tensor is garanteed to be
      * contiguous as well.
-     * 
+     *
      * @param coordIdx Coordinates of the sub-tensor to extract
      * @return Tensor Sub-tensor.
     */
@@ -639,7 +651,7 @@ class Tensor : public Data,
 
     /**
      * Returns a sub-tensor at some coordinate and with some dimension.
-     * 
+     *
      * @param coordIdx First coordinates of the sub-tensor to extract
      * @param dims Dimensions of the sub-tensor to extract
      * @return Tensor Sub-tensor.
@@ -704,7 +716,7 @@ class Tensor : public Data,
      * The data type, backend and device stay the same.
      * @param fallback A shared_ptr to Tensor ready to be overwritten if necessary.
      * The shared_ptr does not need to be initialized. No new memory allocation
-     * will occur if fallback has already been allocated with the right 
+     * will occur if fallback has already been allocated with the right
      * type/size/device.
      * @return Reference to either itself or to fallback.
     */