feat: alternate syntax for threads

engine/tests/src/placeholder.cc

@@ -1 +0,0 @@
-#include <catch2/catch_test_macros.hpp>

engine/tests/src/thread.cc

@@ -0,0 +1,33 @@
+#include "fishbone/thread.h"
+#include <catch2/catch_test_macros.hpp>
+
+struct thread_arg {
+    int& a;
+};
+
+TEST_CASE("Thread") {
+    int a = 0;
+
+    fishbone::Thread th([&a](auto) {
+        for (int i = 0; i < 100; i++) {
+            a++;
+        }
+    });
+
+    th.join();
+    REQUIRE(a == 100);
+    
+    a = 0;
+
+    thread_arg arg { a };
+    fishbone::Thread th2([](auto, void* data) {
+        thread_arg& arg = *static_cast<thread_arg*>(data);
+
+        for (int i = 0; i < 100; i++) {
+            arg.a++;
+        }
+    }, &arg);
+
+    th.join();
+    REQUIRE(a == 100);
+}