Libspinscale: begin splitting it off

libspinscale/include/spinscale/callback.h

@@ -0,0 +1,31 @@
+#ifndef SPINSCALE_CALLBACK_H
+#define SPINSCALE_CALLBACK_H
+
+#include <memory>
+
+namespace smo {
+
+// Forward declaration
+class AsynchronousContinuationChainLink;
+
+/**
+ * @brief Callback class that wraps a function and its caller continuation
+ * 
+ * This class provides a way to pass both a callback function and the
+ * caller's continuation in a single object, enabling deadlock detection
+ * by walking the chain of continuations.
+ *
+ * Usage: Callback<CbFnT>{context, std::bind(...)}
+ */
+template<typename CbFnT>
+class Callback
+{
+public:
+	// Aggregate initialization allows: Callback<CbFnT>{context, std::bind(...)}
+	std::shared_ptr<AsynchronousContinuationChainLink> callerContinuation;
+	CbFnT callbackFn;
+};
+
+} // namespace smo
+
+#endif // SPINSCALE_CALLBACK_H