Split classes into neater header units

include/spinscale/co/returnValues.h

@@ -0,0 +1,61 @@
+#ifndef RETURN_VALUES_H
+#define RETURN_VALUES_H
+
+#include <config.h>
+#include <exception>
+#include <iostream>
+#include <thread>
+#include <type_traits>
+
+namespace sscl::co {
+
+template <typename T, bool IsVoid = std::is_void_v<T>>
+struct ReturnValueStorage;
+
+template <typename T>
+struct ReturnValueStorage<T, false>
+{
+	T myReturnValue{};
+};
+
+template <typename T>
+struct ReturnValueStorage<T, true>
+{
+};
+
+template <typename T>
+struct ReturnValues
+: public ReturnValueStorage<T>
+{
+	ReturnValues() noexcept
+	: myExceptionPtr(myMemberExceptionPtr)
+	{}
+
+	explicit ReturnValues(std::exception_ptr &callerExceptionPtr) noexcept
+	: myExceptionPtr(callerExceptionPtr)
+	{}
+
+	~ReturnValues() noexcept
+	{
+#ifdef CONFIG_LIBSSCL_DEBUG_CO
+		std::cout << __func__ << ": " << std::this_thread::get_id()
+			<< " Destructing.\n";
+#endif
+	}
+
+	/**	EXPLANATION:
+	 * The exception_ptr ref here can either point to the exception_ptr
+	 * a non-viral coroutine supplied to us as its storage space for
+	 * where we should store any exception that is thrown;
+	 *
+	 * Or it could point to the member exception_ptr in this very class,
+	 * which is used for viral coroutines that can bubble their exception
+	 * up and automatically via the language runtime.
+	 */
+	std::exception_ptr &myExceptionPtr;
+	std::exception_ptr myMemberExceptionPtr = nullptr;
+};
+
+} // namespace sscl::co
+
+#endif // RETURN_VALUES_H