Thread: Determine the type of a struct at runtime

Hello,

My data is coming in the form of a pointer to void. My aim is to dump the data to stderr in a structured way. The data pointed to by the struct is a struct that could be of several types. In order to print this data out in a structured way, there is the need to determine its type.

Code:

static void dump(const char *prefix, size_t size)
{
     //cur_data is a global variable, we wish to print out the struct pointed to by it
}

My first thought is that we can use sizeof such that, if the size of the global variable 'cur_data' equal the size of the a certain struct, then we can assume that the contents of the global variable is the said struct.

Code:

size_t struct_size = sizeof(*cur_data);

switch(struct_size){
   
   case sizeof(struct A):

   case sizeof(struct B):

   case sizeof(struct C);

   default:

}

Could someone know of a better way to do this?