Don't bother supporting a filename

lib/include/aocpp/Startup.hpp

@@ -8,15 +8,6 @@
 #include <memory>
 #include <optional>
 
-namespace aocpp {
-
-/// @brief Return the selected input stream or run the test suite
-/// @param argc Number of arguments
-/// @param argv Command line arguments
-auto Startup(int argc, char ** argv) -> std::unique_ptr<std::istream, void(*)(std::istream*)>;
-
-}
-
 auto Main(std::istream & in, std::ostream & out) -> void;
 
 #endif

lib/src/Startup.cpp

@@ -10,30 +10,14 @@
 #define DOCTEST_CONFIG_IMPLEMENT
 #include <doctest.h>
 
-namespace aocpp {
-
-auto Startup(int argc, char ** argv) -> std::unique_ptr<std::istream, void(*)(std::istream*)> {
-  if (std::getenv("DOCTEST")) {
-    exit(doctest::Context{argc, argv}.run());
-  }
-
-  switch (argc) {
-    case 2:
-      return {new std::ifstream{argv[1]}, [](std::istream* p) { delete p; }};
-    case 1:
-      return {&std::cin, [](std::istream*){}};
-    default:
-      std::cerr << "bad arguments\n";
-      exit(EXIT_FAILURE);
-  }
-}
-
-}
-
 auto main(int argc, char ** argv) -> int
 {
+  if (std::getenv("DOCTEST")) {
+      return doctest::Context{argc, argv}.run();
+  }
+
   try {
-    Main(*aocpp::Startup(argc, argv), std::cout);
+    Main(std::cin, std::cout);
   } catch (std::exception const& e) {
     std::cerr << "Program failed: " << e.what() << std::endl;
     return 1;