dont compile if we don't have MIDI support underlying (nrf52840 for example)

ladyada · ladyada · commit 3c8a955900d4 · 2019-10-11T16:39:23.000-04:00
diff --git a/src/Adafruit_USBD_MIDI.cpp b/src/Adafruit_USBD_MIDI.cpp
@@ -24,7 +24,7 @@
 
 #include "Adafruit_USBD_MIDI.h"
 
-#if CFG_TUD_MIDI
+#if CFG_TUD_MIDI && defined(TUD_MIDI_DESC_HEAD_LEN)
 
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
