why cant we pass &array to function where &array[0] is possible

Question

void fun(int* array){}  


int main(){

int array[]={1,2,3};
fun(&array);----->(1)//error in this line
return 0;
}

error: cannot convert â

Answer 1

In C++11 if you run this:

#include
template
void foo(T t) {
  std::cout << __PRETTY_FUNCTION__ << std::endl;
}

int main() {
   int arr[] = {1,2,3};
   foo(arr);
   foo(arr);
   foo(&arr);
   foo(&arr[0]);
}

It will produce the result:

void foo(T) [with T = int*]
void foo(T) [with T = int [3]]
void foo(T) [with T = int (*)[3]]
void foo(T) [with T = int*]

Interestingly, the array collapses into a pointer by default (not sure if this is gcc behaviour or expected). However, the second line shows that the type of arr is int[3], and so &arr is a pointer to int[3] which is different than int*.