assigning struct in switch not working - c

Question

In my program, I'm trying to create a new struct based od switch statement, but when I do so, the compiler returns an error:
Syntax error before '{' token on the row with the position assignment
I'm using dev-c++ 4.9.9.2 as an IDE (i think it's using MinGW as compiler). IT's for my brother's programming assignment I'm helping him with, I haven't seen C in a few years, so I'm rusty (and I wasn't a champion before either).
Here's simplified code:
typedef enum{TOP_RIGHT = 0,TOP_LEFT,BOTTOM_RIGHT,BOTTOM_LEFT} diagonal_t;
typedef struct
{
int row;
int column;
} position_t;
...
void checkDiagonal(diagonal_t diagonal_to_check)
{
...
position_t position;
switch(diagonal_to_check)
{
case TOP_RIGHT:
position = {0,0}; //here's the error, but I don't know how to repair it.
//how to create a new struct here without disrupting the
//switch?
break;
case TOP_LEFT:
position = {0,0};
break;
....
}
}

Answer 1

The var_of_type_struct = { init_value } syntax works only in definitions; it does not work in assignments.
Three common ways to deal with is are
Defining a function that initializes your struct
Defining a function that sets fields to parameters that you pass, and
Assigning the individual fields of your struct.
Approach 1:
void init_pos(position_t *p) {
p->row = 0;
p->column = 0;
}
...
case TOP_LEFT:
init_pos(&position);
break;
Approach 2:
void set_pos(position_t *p, int r, int c) {
p->row = r;
p->column = c;
}
...
case TOP_LEFT:
set_pos(&position, 0, 0);
break;
Approach 3:
case TOP_LEFT:
position.row = 0;
position.column = 0;
break;

Answer 2

You can't do that: assignment and initialization are not the same thing. You are attempting to use initializer syntax in an assignment. You'll have to set both fields manually:
case TOP_RIGHT:
position.row = 0;
position.column = 0;
/* ... */

Answer 3

You need to cast to struct type, like this:
position = (position_t){0, 0};