From f32afb70b8b53e69362b01a3806ea7655589e4b5 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Fri, 4 Jul 2025 11:02:23 +0200
Subject: [PATCH] Add contract to create thread.

---
 lib/std/threads/thread.c3 | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/std/threads/thread.c3 b/lib/std/threads/thread.c3
index 26614bc1d..96fd39bfd 100644
--- a/lib/std/threads/thread.c3
+++ b/lib/std/threads/thread.c3
@@ -68,7 +68,16 @@ macro void? ConditionVariable.wait_timeout(&cond, Mutex* mutex, ulong ms)
 	return NativeConditionVariable.wait_timeout((NativeConditionVariable*)cond, (NativeMutex*)mutex, ms);
 }
 
-macro void? Thread.create(&thread, ThreadFn thread_fn, void* arg) => NativeThread.create(thread, thread_fn, arg);
+<*
+ Create and start a thread.
+
+ @require thread_fn != null : "A non null thread function is required"
+*>
+macro void? Thread.create(&thread, ThreadFn thread_fn, void* arg)
+{
+	return NativeThread.create(thread, thread_fn, arg);
+}
+
 macro void? Thread.detach(thread) => NativeThread.detach(thread);
 macro int? Thread.join(thread) => NativeThread.join(thread);
 macro bool Thread.equals(thread, Thread other) => NativeThread.equals(thread, other);