feat(wire): adds std::functional to slave callback functions

Author: SuGlider

cores/esp32/HardwareI2C.h

@@ -20,6 +20,7 @@
 
 #include <inttypes.h>
 #include "Stream.h"
+#include <functional>
 
 class HardwareI2C : public Stream {
 public:
@@ -36,6 +37,7 @@ class HardwareI2C : public Stream {
   virtual size_t requestFrom(uint8_t address, size_t len, bool stopBit) = 0;
   virtual size_t requestFrom(uint8_t address, size_t len) = 0;
 
-  virtual void onReceive(void (*)(int)) = 0;
-  virtual void onRequest(void (*)(void)) = 0;
+  // Update base class to use std::function
+  virtual void onReceive(std::function<void(int)>) = 0;
+  virtual void onRequest(std::function<void()>) = 0;
 };