added invalid newline char detection, cleanup

cellular_automaton/wireworld_c++/FileIO.cpp

 #include "FileIO.hpp"
 
 #include <algorithm>
+#include <array>
 #include <fstream>
 #include <iomanip>
-#include <array>
 #include <iostream>
 #include <sstream>
 
@@ -17,6 +17,10 @@ HeaderInfo FileIO::ReadHeader(const std::string& path) {
 	MPI_File_read_all(fh, buf.data(), buf.size(), MPI_CHAR, MPI_STATUS_IGNORE);
 	MPI_File_close(&fh);
 
+	if (std::find(std::begin(buf), std::end(buf), '\r') != std::end(buf)) {
+		MpiReportErrorAbort("Invalid newline character detected!");
+	}
+
 	// make stream from buf
 	std::istringstream input;
 	input.rdbuf()->pubsetbuf(buf.data(), buf.size());

cellular_automaton/wireworld_c++/MpiEnvironment.cpp

@@ -15,6 +15,8 @@ MpiEnvironment::MpiEnvironment(int& argc, char* argv[]) {
 	MPI_Comm_rank(MPI_COMM_WORLD, &_worldRank);
 	MPI_Comm_size(MPI_COMM_WORLD, &_worldSize);
 	_isMaster = {_worldRank == 0};
+	// We want the program to stop on I/O errors
+	MPI_File_set_errhandler(MPI_FILE_NULL, MPI_ERRORS_ARE_FATAL);
 }
 MpiEnvironment::~MpiEnvironment() {
 	if (_worldRank != -1) { MPI_Finalize(); }

cellular_automaton/wireworld_c++/main.cpp

-#include <cassert>
 #include <chrono>
 #include <cstdlib>
-#include <fstream>
 #include <iostream>
-#include <string>
-#include <thread>
-#include <vector>
 
 #include "Configuration.hpp"
 #include "MpiEnvironment.hpp"
@@ -16,12 +11,12 @@ using namespace std::string_literals;
 int main(int argc, char* argv[]) {
 	const auto& starttime = std::chrono::system_clock::now();
 
+	// we rely on the MPI implementation to correctly forward the arguments
 	MpiEnvironment env(argc, argv);
-	const auto& cfg = Configuration::parseArgs(argc, argv, env);
+	const auto cfg = Configuration::parseArgs(argc, argv, env);
 
 	MpiWireworld ww(env, cfg);
 
-
 	for (std::size_t i{0}; i < cfg.Generations; ++i) {
 		ww.simulateStep();
 
@@ -29,6 +24,7 @@ int main(int argc, char* argv[]) {
 			std::cout << "iteration:" << i << '\n';
 		}
 	}
+	// write output file if needed
 	if (!cfg.OutputFilePath.empty()) { ww.write(); }
 
 	if (env.isMaster()) {