Graceful failing on missing data

main.cpp

@@ -6,27 +6,33 @@
 #include <boost/filesystem/fstream.hpp>
 #include <string>*/
 
+#include <exception>
 #include "DescriptorManager.h"
 #include <boost/filesystem.hpp>
 #include <Magick++.h>
-using namespace std;
 using namespace Magick;
 
 enum method {avg_color, num_color, median, sobel, pearson, threshold, dct_pearson, dct_median};
 
 int main(int argc, char **argv) {
-	string imagename = "im3102.jpg";
+	std::string imagename = "im3102.jpg";
 	int method = method::median;
 	if (argc > 2) {
 		method = atoi(argv[2]);
 		imagename = argv[1];
 	}
 	else {
-		cout << "Usage: " << endl << argv[0] << " [fileName] [methodIndex]" << endl;
-		cout << "Continuing.." << endl;
+		std::cout << "Usage: " << std::endl << argv[0] << " [fileName] [methodIndex]" << std::endl;
+		std::cout << "Continuing.." << std::endl;
 	}
 	InitializeMagick(*argv);
-	DescriptorManager* manager = new DescriptorManager("data"); 
+	DescriptorManager* manager;
+	try {
+		manager = new DescriptorManager("data"); 
+	} catch (const std::exception& e) {
+		std::cout << "Creating manager failed: " << e.what() << std::endl;
+		return -1;
+	}
 	manager->Init();/*
 	manager->rankImages(imagename, method);
 	manager->outputRank(imagename, method);