FIX: Added exceptions to not implemented functions

src/Neuron/NeuronAbsolute.cpp

@@ -33,7 +33,7 @@ namespace lib4neuro {
 
 
 	Neuron* NeuronAbsolute::get_derivative() {//TODO: implement this function correctly
-		THROW_NOT_IMPLEMENTED_ERROR("");
+		THROW_NOT_IMPLEMENTED_ERROR("The derivative of Absolute neuron is not implemented yet");
 	}
 
 }
\ No newline at end of file

src/Neuron/NeuronFilter.cpp

@@ -6,6 +6,7 @@
 #include "Neuron.h"
 #include "NeuronSerialization.h"
 #include "NeuronFilterSerialization.h"
+#include "exceptions.h"
 
 BOOST_CLASS_EXPORT_IMPLEMENT(lib4neuro::NeuronFilter);
 
@@ -32,8 +33,7 @@ namespace lib4neuro {
     }
 
     Neuron* NeuronFilter::get_derivative() {
-        NeuronBinary* output = new NeuronBinary();
-        return output;
+		THROW_NOT_IMPLEMENTED_ERROR("The derivative of Filter neuron is not implemented yet");
     }
 
 

src/Neuron/NeuronLinearSaturated.cpp

@@ -57,7 +57,7 @@ namespace lib4neuro {
     }
 
     Neuron* NeuronLinearSaturated::get_derivative() {
-        THROW_NOT_IMPLEMENTED_ERROR("");
+        THROW_NOT_IMPLEMENTED_ERROR("The derivative of Linear Saturated neuron is not implemented yet");
     }