CODEWITHSUNDEEP
cpointers
Shane
Shane

Reputation: 2375

Conflicting types for function and a cast warning?

I'm sure this is an easy answer for someone with experience with pointers in c, but I am struggling at the moment to see my error. I get a warning that the return call from a function makes a pointer from integer, even though the return type of the function is a pointer. And get the error that the function has conflicting types. Here is the code, I have removed the body of the function and I still get the error and warning.

long long *merge_sort(long long * arr, int size){
// Arrays shorter than 1 are already sorted
if(size > 1){
    int middle = size / 2, i; 
    long long *left, *right;
    left = arr;
    right = arr + middle; 

    left = merge_sort(left, middle);
    right = merge_sort(right, size-middle);
    return merge(left,right);
}else { return arr;  }
}

long long *merge(long long * left, long long * right){

}

Upvotes: 0

Views: 1687

Answers (1)

Seth Carnegie
Seth Carnegie

Reputation: 75150

You need to declare your function merge above merge_sort; when the compiler sees a call to a function that hasn't been declared yet, it automatically assumes it returns an int:

// forward declaration
long long *merge(long long * left, long long * right);

long long *merge_sort(long long * arr, int size){
// Arrays shorter than 1 are already sorted
if(size > 1){
    int middle = size / 2, i; 
    long long *left, *right;
    left = arr;
    right = arr + middle; 

    left = merge_sort(left, middle);
    right = merge_sort(right, size-middle);
    return merge(left,right);
}else { return arr;  }
}

long long *merge(long long * left, long long * right){

}

Upvotes: 7

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