Throw an exception if number of neural net layer sizes & activation types do not match

libs/ml/include/psemek/ml/neural_net.hpp

@@ -4,7 +4,7 @@
 #include <psemek/random/uniform.hpp>
 
 #include <vector>
-#include <exception>
+#include <stdexcept>
 
 namespace psemek::ml
 {
@@ -15,6 +15,12 @@ namespace psemek::ml
 		char const * what() noexcept;
 	};
 
+	struct wrong_activation_types_count_error
+		: std::runtime_error
+	{
+		wrong_activation_types_count_error(std::size_t expected, std::size_t actual);
+	};
+
 	namespace detail
 	{
 
@@ -98,6 +104,9 @@ namespace psemek::ml
 	{
 		if (layer_sizes_.empty())
 			throw empty_neural_net_error{};
+
+		if (layer_sizes_.size() != activation_types_.size() + 1)
+			throw wrong_activation_types_count_error{layer_sizes_.size() - 1, activation_types_.size()};
 	}
 
 	template <typename T>

libs/ml/source/neural_net.cpp

@@ -1,5 +1,7 @@
 #include <psemek/ml/neural_net.hpp>
 
+#include <psemek/util/to_string.hpp>
+
 namespace psemek::ml
 {
 
@@ -8,6 +10,10 @@ namespace psemek::ml
 		return "neural net must have at least a single layer";
 	}
 
+	wrong_activation_types_count_error::wrong_activation_types_count_error(std::size_t expected, std::size_t actual)
+		: std::runtime_error(util::to_string("wrong number of activation types: expected ", expected, ", got ", actual))
+	{}
+
 	template struct neural_net<float>;
 	template struct neural_net<double>;