diff --git a/unit_tests/operator/Test_ConcatImpl.cpp b/unit_tests/operator/Test_ConcatImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..184c02d5208c99b903cf838784bb14fb65799111
--- /dev/null
+++ b/unit_tests/operator/Test_ConcatImpl.cpp
@@ -0,0 +1,143 @@
+/********************************************************************************
+ * Copyright (c) 2023 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/data/Tensor.hpp"
+#include "aidge/operator/Add.hpp"
+#include "aidge/operator/Concat.hpp"
+
+using namespace Aidge;
+
+TEST_CASE("[cpu/operator] Concat(forward)", "[Concat][CPU]") {
+ SECTION("Concat 1D inputs") {
+ std::shared_ptr<Tensor> input1 = std::make_shared<Tensor>(Array1D<int,2>{{ 2, 3 }});
+ std::shared_ptr<Tensor> input2 = std::make_shared<Tensor>(Array1D<int,3>{{ 4, 5, 6 }});
+ std::shared_ptr<Tensor> input3 = std::make_shared<Tensor>(Array1D<int,4>{{ 7, 8, 9, 10 }});
+ std::shared_ptr<Tensor> input4 = std::make_shared<Tensor>(Array1D<int,5>{{ 11, 12, 13, 14, 15 }});
+ std::shared_ptr<Tensor> input5 = std::make_shared<Tensor>(Array1D<int,6>{{ 16, 17, 18, 19, 20, 21 }});
+
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array1D<int,20>{
+ { 2, 3, 4, 5, 6, 7, 8, 9, 10,11,12,13,14,15,16,17,18,19,20,21 }});
+
+ auto myConcat = Concat(5, 0);
+ myConcat->getOperator()->associateInput(0, input1);
+ myConcat->getOperator()->associateInput(1, input2);
+ myConcat->getOperator()->associateInput(2, input3);
+ myConcat->getOperator()->associateInput(3, input4);
+ myConcat->getOperator()->associateInput(4, input5);
+ myConcat->getOperator()->setBackend("cpu");
+ myConcat->getOperator()->setDataType(DataType::Int32);
+ myConcat->forward();
+
+ std::static_pointer_cast<Tensor>(myConcat->getOperator()->getRawOutput(0))->print();
+
+ REQUIRE(*std::static_pointer_cast<OperatorTensor>(myConcat->getOperator())->getOutput(0) == *expectedOutput);
+ }
+ SECTION("Concat 4D inputs on 1st axis") {
+ std::shared_ptr<Tensor> input1 = std::make_shared<Tensor>(Array4D<int,1,3,3,2> {
+ { //
+ { //
+ {{20, 47},{21, 48},{22, 49}}, //
+ {{23, 50},{24, 51},{25, 52}}, //
+ {{26, 53},{27, 54},{28, 55}} //
+ }, //
+ } //
+ }); //
+ std::shared_ptr<Tensor> input2 = std::make_shared<Tensor>(Array4D<int,2,3,3,2> {
+ {
+ { //
+ {{29, 56},{30, 57},{31, 58}}, //
+ {{32, 59},{33, 60},{34, 61}}, //
+ {{35, 62},{36, 63},{37, 64}} //
+ }, //
+ { //
+ {{38, 65},{39, 66},{40, 67}}, //
+ {{41, 68},{42, 69},{43, 70}}, //
+ {{44, 71},{45, 72},{46, 73}} //
+ } //
+ } //
+ }); //
+
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array4D<int,3,3,3,2> {
+ { //
+ { //
+ {{20, 47},{21, 48},{22, 49}}, //
+ {{23, 50},{24, 51},{25, 52}}, //
+ {{26, 53},{27, 54},{28, 55}} //
+ }, //
+ { //
+ {{29, 56},{30, 57},{31, 58}}, //
+ {{32, 59},{33, 60},{34, 61}}, //
+ {{35, 62},{36, 63},{37, 64}} //
+ }, //
+ { //
+ {{38, 65},{39, 66},{40, 67}}, //
+ {{41, 68},{42, 69},{43, 70}}, //
+ {{44, 71},{45, 72},{46, 73}} //
+ } //
+ } //
+ }); //
+
+ auto myConcat = Concat(2, 0);
+ myConcat->getOperator()->associateInput(0, input1);
+ myConcat->getOperator()->associateInput(1, input2);
+ myConcat->getOperator()->setBackend("cpu");
+ myConcat->getOperator()->setDataType(DataType::Int32);
+ myConcat->forward();
+
+ std::static_pointer_cast<OperatorTensor>(myConcat->getOperator())->getOutput(0)->print();
+
+ REQUIRE(*std::static_pointer_cast<OperatorTensor>(myConcat->getOperator())->getOutput(0) == *expectedOutput);
+ }
+
+ SECTION("Concat 4D inputs on 3rd axis") {
+ std::shared_ptr<Tensor> input1 = std::make_shared<Tensor>(Array4D<int,1,3,3,2> {
+ { //
+ { //
+ {{20, 47},{21, 48},{22, 49}}, //
+ {{23, 50},{24, 51},{25, 52}}, //
+ {{26, 53},{27, 54},{28, 55}} //
+ }, //
+ } //
+ }); //
+ std::shared_ptr<Tensor> input2 = std::make_shared<Tensor>(Array4D<int,1,3,6,2> {
+ {
+ { //
+ {{29, 56},{30, 57},{31, 58},{38, 65},{39, 66},{40, 67}}, //
+ {{32, 59},{33, 60},{34, 61},{41, 68},{42, 69},{43, 70}}, //
+ {{35, 62},{36, 63},{37, 64},{44, 71},{45, 72},{46, 73}} //
+ },
+ }
+ });
+
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array4D<int,1,3,9,2> {
+ { //
+ { //
+ {{20, 47},{21, 48},{22, 49},{29, 56},{30, 57},{31, 58},{38, 65},{39, 66},{40, 67}}, //
+ {{23, 50},{24, 51},{25, 52},{32, 59},{33, 60},{34, 61},{41, 68},{42, 69},{43, 70}}, //
+ {{26, 53},{27, 54},{28, 55},{35, 62},{36, 63},{37, 64},{44, 71},{45, 72},{46, 73}} //
+ }, //
+ } //
+ }); //
+
+ auto myConcat = Concat(2, 2);
+ myConcat->getOperator()->associateInput(0, input1);
+ myConcat->getOperator()->associateInput(1, input2);
+ myConcat->getOperator()->setBackend("cpu");
+ myConcat->getOperator()->setDataType(DataType::Int32);
+ myConcat->forward();
+
+ std::static_pointer_cast<Tensor>(myConcat->getOperator()->getRawOutput(0))->print();
+
+ REQUIRE(*std::static_pointer_cast<OperatorTensor>(myConcat->getOperator())->getOutput(0) == *expectedOutput);
+ }
+}
\ No newline at end of file
diff --git a/unit_tests/operator/Test_GatherImpl.cpp b/unit_tests/operator/Test_GatherImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..2995963a35cda5b0c5794b1d15e4064438b58ece
--- /dev/null
+++ b/unit_tests/operator/Test_GatherImpl.cpp
@@ -0,0 +1,96 @@
+/********************************************************************************
+ * Copyright (c) 2023 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/data/Tensor.hpp"
+#include "aidge/operator/Gather.hpp"
+
+#include <memory>
+
+
+using namespace Aidge;
+
+TEST_CASE("[cpu/operator] Gather(forward)") {
+ SECTION("2D Tensor axis 0") {
+ std::shared_ptr<Tensor> input = std::make_shared<Tensor>(Array2D<int,3,3> {
+ {
+ {1, 2, 3},
+ {4, 5, 6},
+ {7, 8, 9}
+ }
+ });
+ std::shared_ptr<Tensor> indexes = std::make_shared<Tensor>(Array2D<int,1,2> {
+ {
+ {1, 2}
+ }
+ });
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array3D<int,1,2,3> {
+ {
+ {
+ {4, 5, 6},
+ {7, 8, 9}
+ }
+ }
+ });
+
+ std::shared_ptr<Node> myGather = Gather({1, 2}, {1, 2}, 0);
+ auto op = std::static_pointer_cast<OperatorTensor>(myGather -> getOperator());
+ op->associateInput(0,input);
+ // op->associateInput(1,indexes);
+ op->setDataType(DataType::Int32);
+ op->setBackend("cpu");
+ myGather->forward();
+ op->getOutput(0)->print();
+ expectedOutput->print();
+
+ REQUIRE(*(op->getOutput(0)) == *expectedOutput);
+
+ }
+ SECTION("2D Tensor axis 1") {
+ std::shared_ptr<Tensor> input = std::make_shared<Tensor>(Array2D<int,3,3> {
+ {
+ {1, 2, 3},
+ {4, 5, 6},
+ {7, 8, 9}
+ }
+ });
+ std::shared_ptr<Tensor> indexes = std::make_shared<Tensor>(Array2D<int,1,2> {
+ {
+ {0, 2}
+ }
+ });
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array3D<int,3,1,2> {
+ {
+ {
+ {1, 3}
+ },
+ {
+ {4, 6}
+ },
+ {
+ {7, 9}
+ }
+ }
+ });
+
+ std::shared_ptr<Node> myGather = Gather({0, 2}, {1, 2}, 1);
+ auto op = std::static_pointer_cast<OperatorTensor>(myGather -> getOperator());
+ op->associateInput(0,input);
+ // op->associateInput(1,indexes);
+ op->setDataType(DataType::Int32);
+ op->setBackend("cpu");
+ myGather->forward();
+
+ REQUIRE(*(op->getOutput(0)) == *expectedOutput);
+
+ }
+}
\ No newline at end of file
diff --git a/unit_tests/operator/Test_ReshapeImpl.cpp b/unit_tests/operator/Test_ReshapeImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5d28005eb40534742aae495948e5269373b81ad1
--- /dev/null
+++ b/unit_tests/operator/Test_ReshapeImpl.cpp
@@ -0,0 +1,67 @@
+/********************************************************************************
+ * Copyright (c) 2023 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/data/Tensor.hpp"
+#include "aidge/operator/Reshape.hpp"
+
+#include <memory>
+
+using namespace Aidge;
+
+TEST_CASE("[cpu/operator] Reshape(forward)") {
+ SECTION("1D Tensor") {
+ std::shared_ptr<Tensor> input = std::make_shared<Tensor>(Array1D<float,6> {
+ {1.0, 2.0, 3.0, 4.0, 5.0, 6.0}
+ });
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array2D<float,2,3> {
+ {
+ {1.0, 2.0, 3.0},
+ {4.0, 5.0, 6.0}
+ }
+ });
+
+ std::shared_ptr<Node> myReshape = Reshape({2, 3});
+ auto op = std::static_pointer_cast<OperatorTensor>(myReshape -> getOperator());
+ op->associateInput(0, input);
+ op->setDataType(DataType::Float32);
+ op->setBackend("cpu");
+ myReshape->forward();
+
+ REQUIRE(*(op->getOutput(0)) == *expectedOutput);
+ }
+ SECTION("2D Tensor") {
+ std::shared_ptr<Tensor> input = std::make_shared<Tensor>(Array2D<float,2,3> {
+ {
+ {1.0, 2.0, 3.0},
+ {4.0, 5.0, 6.0}
+ }
+
+ });
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array2D<float,3,2> {
+ {
+ {1.0, 2.0},
+ {3.0, 4.0},
+ {5.0, 6.0}
+ }
+ });
+
+ std::shared_ptr<Node> myReshape = Reshape({3, 2});
+ auto op = std::static_pointer_cast<OperatorTensor>(myReshape -> getOperator());
+ op->associateInput(0, input);
+ op->setDataType(DataType::Float32);
+ op->setBackend("cpu");
+ myReshape->forward();
+
+ REQUIRE(*(op->getOutput(0)) == *expectedOutput);
+ }
+}
\ No newline at end of file