Casting to global variable from LPVOID - C

Question

I am trying to cast data to a struct from a parameter passed into my method, I need the data to be passed to a global variable as it is needed elsewhere in my application.

I have tried the following but I get errors saying that diceResult is an undeclared identifier

Here is the code itself:

//Structure to hold dice data
typedef struct diceData
{
    int dice1;
    int dice2;
};

struct diceResult;

DWORD WINAPI UnpackDiceData(LPVOID sentData)
{
    //Unpack data
    struct diceData unpackedData = *((struct diceData*)sentData);

    diceResult.dice1 = unpackedData.dice1;
    diceResult.dice2 = unpackedData.dice2;
}

I don't understand why it won't recognise it being there when it's clearly global.

Answer 1

typedef struct diceData
{
    int dice1;
    int dice2;
};

Your typedef isn't doing anything. Normally you'd use it something like:

typedef struct { 
    int dice1;
    int dice2;
} diceData;

Then you can define an instance of that type:

diceData diceResult;

... and then your other code should be able to use that instance.

When you have that working, my advice would to rewrite it so it does not use global data.