Differences between struct in C and C++

Question

I am trying to convert a C++ struct to C but keep getting "undeclared identifier"? Does C++ have a different syntax for referring to structs?

struc         


        

Answer 1

In C, the name of the type is struct KEY_STATE.

So you have to declare the second struct as

typedef struct _DEVICE_EXTENSION
{
    WDFDEVICE WdfDevice;
    struct KEY_STATE kState;
} DEVICE_EXTENSION, *PDEVICE_EXTENSION;

If you do not want to write struct all the time, you can use a typedef declare KEY_STATE similar to DEVICE_EXTENSION:

typedef struct _KEY_STATE
{
    /* ... */
} KEY_STATE;