get rid of global variable for default value

src/aevol_create.cpp

@@ -42,8 +42,6 @@
 #include "parameters/ParamLoader.h"
 #include "parameters/ParamReader.h"
 
-const std::string DEFAULT_PARAM_FILE_NAME = "param.in";
-
 using namespace aevol;
 
 // Helper functions
@@ -123,7 +121,7 @@ void print_help(char* prog_path) {
 
 auto interpret_cmd_line_options(int argc, char* argv[]) -> std::tuple<std::string, std::string> {
   // Command-line option variables
-  std::string param_file_name;
+  std::string param_file_name = "param.in";
   std::string chromosome_file_name;
 
   // Define allowed options
@@ -165,11 +163,6 @@ auto interpret_cmd_line_options(int argc, char* argv[]) -> std::tuple<std::strin
     }
   }
 
-  // Set undefined command line parameters to default values
-  if (param_file_name.length() == 0) {
-    param_file_name = DEFAULT_PARAM_FILE_NAME;
-  }
-
   return std::make_tuple(param_file_name, chromosome_file_name);
 }