further writing CMakeLists.txt

src/main.cpp

@@ -0,0 +1,15 @@
+#include <argparse/argparse.hpp>
+#include <string>
+const std::string main_version = "0.0.1";
+const std::string build_version = GIT_COMMIT_HASH;
+int main(int argc, char *argv[]) {
+  argparse::ArgumentParser program("backend", main_version + "-" + build_version);
+  try {
+    program.parse_args(argc, argv);
+  } catch (const std::exception &err) {
+    std::cerr << err.what() << std::endl;
+    std::cerr << program;
+    return 1;
+  }
+  return 0;
+}