gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#define UNUSED(x)               (void)(x)
typedef unsigned char uint8_t;

typedef struct
	uint8_t (*send)(uint8_t *data, uint8_t len);
	uint8_t (*read)(uint8_t *data, uint8_t len);
} interface;

uint8_t uart1send(void *p_context){
	UNUSED(p_context);
  printf("%d", (int)p_context);
	return 1;
}


int main(void){
	interface uart1, uart2;
	uart1.send = uart1send;
	uart1.send((void*)'a');
  uart2.send = uart1send;
  uart1.send((void*)'b');
  
	return 0;
}