Fixed 2nd output handling

include/aidge/operator/TopK.hpp

@@ -94,6 +94,7 @@ public:
     bool forwardDims(bool allowDataDependency = false) override final;
 
     void setBackend(const std::string& name, DeviceIdx_t device = 0) override;
+    void setDataType(const DataType& dataType) const override final;
     std::set<std::string> getAvailableBackends() const override;
 
     inline std::shared_ptr<Attributes> attributes() const override { return mAttributes; }

src/operator/TopK.cpp

@@ -78,6 +78,8 @@ bool Aidge::TopK_Op::forwardDims(bool allowDataDependency) {
         const auto kAxis = (axis() >= 0) ? axis() : axis() + static_cast<std::int8_t>(outDims.size());
         outDims[kAxis] = k();
         mOutputs[0]->resize(outDims);
+        mOutputs[1]->resize(outDims);
+        mOutputs[1]->setDataType(DataType::Int64);
         return true;
     }
 
@@ -87,6 +89,12 @@ bool Aidge::TopK_Op::forwardDims(bool allowDataDependency) {
 void Aidge::TopK_Op::setBackend(const std::string& name, Aidge::DeviceIdx_t device) {
     SET_IMPL_MACRO(TopK_Op, *this, name);
     mOutputs[0]->setBackend(name, device);
+    mOutputs[1]->setBackend(name, device);
+}
+
+void Aidge::TopK_Op::setDataType(const DataType& dataType) const {
+    mOutputs[0]->setDataType(dataType);
+    // mOutputs[1] data type is fixed (Int64)
 }
 
 std::set<std::string> Aidge::TopK_Op::getAvailableBackends() const {