very, very simple WP with midi CC out

include/libremidi/output_configuration.hpp

@@ -0,0 +1,23 @@
+#pragma once
+#include <libremidi/config.hpp>
+#include <libremidi/error.hpp>
+#include <libremidi/input_configuration.hpp>
+
+#include <string>
+
+namespace libremidi
+{
+struct output_configuration
+{
+  //! Set an error callback function to be invoked when an error has occured.
+  /*!
+    The callback function will be called whenever an error has occured. It is
+    best to set the error callback function before opening a port.
+  */
+  midi_error_callback on_error{};
+  midi_error_callback on_warning{};
+
+  //! Timestamp mode for the timestamps passed to schedule_message
+  uint32_t timestamps : 3 = timestamp_mode::Absolute;
+};
+}