ADD: added a new connection type to represent a never-changing edge

src/NetConnection/ConnectionFunctionConstant.cpp

+/**
+ * DESCRIPTION OF THE FILE
+ *
+ * @author Michal Kravčenko
+ * @date 15.3.19 -
+ */
+
+#include "ConnectionFunctionConstant.h"
+
+ConnectionFunctionConstant::ConnectionFunctionConstant(double w) {
+    this->weight = w;
+}
+
+ConnectionFunctionConstant::~ConnectionFunctionConstant() {
+
+}
+
+double ConnectionFunctionConstant::eval(std::vector<double> &parameter_space) {
+    return this->weight;
+}
+
+void ConnectionFunctionConstant::eval_partial_derivative(std::vector<double> &parameter_space,
+                                                 std::vector<double> &weight_gradient, double alpha) {
+
+}
\ No newline at end of file

src/NetConnection/ConnectionFunctionConstant.h

+/**
+ * DESCRIPTION OF THE FILE
+ *
+ * @author Michal Kravčenko
+ * @date 15.3.19 -
+ */
+
+#ifndef LIB4NEURO_CONNECTIONFUNCTIONCONSTANT_H
+#define LIB4NEURO_CONNECTIONFUNCTIONCONSTANT_H
+
+#include "../settings.h"
+#include "ConnectionFunctionGeneral.h"
+
+class ConnectionFunctionConstant:public ConnectionFunctionGeneral {
+private:
+    double weight;
+public:
+
+    LIB4NEURO_API ConnectionFunctionConstant(double w);
+
+    LIB4NEURO_API ~ConnectionFunctionConstant();
+
+    LIB4NEURO_API double eval( std::vector<double> &parameter_space ) override;
+
+    LIB4NEURO_API void eval_partial_derivative(std::vector<double> &parameter_space, std::vector<double> &weight_gradient, double alpha) override;
+
+};
+
+
+#endif //LIB4NEURO_CONNECTIONFUNCTIONCONSTANT_H