Figured out threads for the next round.

meson.build

@@ -36,6 +36,7 @@ executable('escape_turings_tarpit',
     'builder.cpp',
     'sfmlgui.cpp',
     'escape_turings_tarpit.cpp'],
+  win_subsystem: 'windows',
   dependencies: dependencies)
 
 executable('regtest', 'regtest.cpp',
@@ -53,6 +54,9 @@ executable('audiotest', 'audiotest.cpp',
 executable('jsontest', 'jsontest.cpp',
   dependencies: dependencies)
 
+executable('threadtest', 'threadtest.cpp',
+  dependencies: dependencies)
+
 runtests = executable('runtests', [
   'game_engine.cpp',
   'tests/game_engine.cpp',

threadtest.cpp

@@ -0,0 +1,34 @@
+#include <thread>
+#include <fmt/core.h>
+#include <chrono>
+#include <iostream>
+#include <thread>
+#include <utility>
+#include <iostream>
+#include <mutex>
+
+using namespace std::chrono_literals;
+
+std::atomic_int counter = 0;
+std::mutex counter_mutex;
+
+
+void locked_counter() {
+  for (int i = 0; i < 5; ++i)
+  {
+    std::lock_guard<std::mutex> lock(counter_mutex);
+    std::this_thread::sleep_for(100ms);
+    std::cout << "Thread 1 executing\n";
+    ++counter;
+  }
+}
+
+int main()
+{
+  std::jthread t2(locked_counter); // pass by value
+
+  for(int i = 0; i < 5; ++i) {
+    std::lock_guard<std::mutex> lock(counter_mutex);
+    std::cout << "counter is " << counter << std::endl;
+  }
+}