Restarted the production of the app

libs/CLI11/examples/groups.cpp

@@ -0,0 +1,39 @@
+// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
+// under NSF AWARD 1414736 and by the respective contributors.
+// All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include <CLI/CLI.hpp>
+#include <CLI/Timer.hpp>
+#include <iostream>
+#include <string>
+
+int main(int argc, char **argv) {
+    CLI::AutoTimer give_me_a_name("This is a timer");
+
+    CLI::App app("K3Pi goofit fitter");
+
+    std::string file;
+    CLI::Option *opt = app.add_option("-f,--file,file", file, "File name")->required()->group("Important");
+
+    int count{0};
+    CLI::Option *copt = app.add_flag("-c,--count", count, "Counter")->required()->group("Important");
+
+    double value{0.0};  // = 3.14;
+    app.add_option("-d,--double", value, "Some Value")->group("Other");
+
+    try {
+        app.parse(argc, argv);
+    } catch(const CLI::ParseError &e) {
+        return app.exit(e);
+    }
+
+    std::cout << "Working on file: " << file << ", direct count: " << app.count("--file")
+              << ", opt count: " << opt->count() << std::endl;
+    std::cout << "Working on count: " << count << ", direct count: " << app.count("--count")
+              << ", opt count: " << copt->count() << std::endl;
+    std::cout << "Some value: " << value << std::endl;
+
+    return 0;
+}