Shove kicad2step into pcbnew itself with a new cli

thirdparty/argparse/samples/compound_arguments.cpp

@@ -0,0 +1,36 @@
+#include <argparse/argparse.hpp>
+
+int main(int argc, char *argv[]) {
+  argparse::ArgumentParser program("test");
+
+  program.add_argument("-a").default_value(false).implicit_value(true);
+
+  program.add_argument("-b").default_value(false).implicit_value(true);
+
+  program.add_argument("-c")
+      .nargs(2)
+      .default_value(std::vector<float>{0.0f, 0.0f})
+      .scan<'g', float>();
+
+  try {
+    program.parse_args(argc, argv); // Example: ./main -abc 1.95 2.47
+  } catch (const std::runtime_error &err) {
+    std::cerr << err.what() << std::endl;
+    std::cerr << program;
+    std::exit(1);
+  }
+
+  auto a = program.get<bool>("-a");               // true
+  auto b = program.get<bool>("-b");               // true
+  auto c = program.get<std::vector<float>>("-c"); // {1.95, 2.47}
+
+  std::cout << "a: " << std::boolalpha << a << "\n";
+  std::cout << "b: " << b << "\n";
+  if (!c.empty()) {
+    std::cout << "c: ";
+    for (auto &v : c) {
+      std::cout << v << " ";
+    }
+    std::cout << std::endl;
+  }
+}