Thread: What enum got to do with it?

Hello
I am having this error problem see comments below.
Can someone help me fix it, I am sure its simple but...
Like chess I do not move until i see it and right now i see nothing wrong?!?!


ERROR CODE:
C:\Program Files\Microsoft Visual Studio\MyProjects\enumerators\enumerator.cpp(73) : error C2676: binary '++' : 'enum month' does not define this operator or a conversion to a type acceptable to the predefined operator


HERE IS MY PROGRAM:
#include<stdio.h>

enum month {jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec};
typedef enum month month;

month previous_month(month M)
{
switch (M)
{
case jan:
M=dec;break;
case feb:
M=jan;break;
case mar:
M=feb;break;
case apr:
M=mar;break;
case may:
M=apr;break;
case jun:
M=may;break;
case jul:
M=jun;break;
case aug:
M=jul;break;
case sep:
M=aug;break;
case oct:
M=sep;break;
case nov:
M=oct;break;
case dec:
M=nov;break;
}
return M;
}

void print_month (month M)
{
switch (M)
{
case jan:
printf("January");break;
case feb:
printf("February");break;
case mar:
printf("March");break;
case apr:
printf("April");break;
case may:
printf("May");break;
case jun:
printf("June");break;
case jul:
printf("July");break;
case aug:
printf("August");break;
case sep:
printf("September");break;
case oct:
printf("October");break;
case nov:
printf("November");break;
case dec:
printf("December");break;
}
}
void main()
{
month M;
printf("Table of months and their predecessors\n");
printf("\n %16s%16s\n", "Month", "Predecessor");
for(M = jan; M <= dec; M++) /*ERROR HERE*/
{
printf("");
print_month(M);
printf("");
print_month(previous_month(M));
putchar('\n');
}
}