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cpointersfunction-pointers
user3331555
user3331555

Reputation: 23

Pointer to a function that takes pointer parameters

I am trying to create a function pointer that takes in a pointer to double as an argument. What is the proper syntax to write in main?

This is what I have but it keeps spitting out errors. 

void (*ptr)(double, double, (*double), (*double) );

Upvotes: 2

Views: 89

Answers (1)

Jason C
Jason C

Reputation: 40305

It is the same way you would declare a double * parameter in a function's parameter list:

void (* ptr) (double, double, double *, double *);

Can be assigned to a function like:

void something (double w, double x, double *py, double *pz) {
}

This is true in the general case, no matter how complicated it gets. For example, a pointer to a function that takes an int and another function pointer (which points to a function that takes a double and a void * and returns a char*) as a parameter:

void (* ptr) (int, char * (*) (double, void *));

Then:

char * g (double w, void *) {
    ...
}

void f (int x, char * (* y) (double, void *)) { 
    ...
}

// usage, elsewhere:
ptr = &f;
ptr(0, &g);

Upvotes: 8

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