c++ - Void pointer initialization? If not, what is it? -

i'm trying understand segment of code used parameter in c++ can't seem find example of elsewhere on internet. here's segment:

void (*cb)(void)

is way of initializing void pointer? benefit of doing versus void *cb?

in example, cb pointer function takes no arguments , has no return value

for example if have

void printhello( ) {     cout << "hello" << endl; }

then later have

void (*cb)(void); cb = printhello;

i can call function using:

cb();

which call printhello();

the utility of can assign different functions cb , call them , pass them around other functions other pointer variable.

often clarity, programmers create specific type avoid having write mouthful:

typedef void (*tprttovoidfn)(void); tptrtovoidfn  cb; cb = printhello;

for comparison, pointer function returns int like:

int (*ptrtofunctionreturningint)(void);

and pointer function taking int , returning nothing like:

void (*ptrtofunctionreturningnothing)(int);

Braziel