Passing by reference to a template function

Question

I'm having a function of finding max and I want to send static array via reference, Why isn't this possible?

template <class T>
T findMax(const T &arr, int size){...}

int main{
  int arr[] = {1,2,3,4,5};
  findMax(arr, 5); // I cannot send it this way, why?
  return 0;
}

Answer 1

Use correct syntax. Change signature to:

template <class T, size_t size>
T findMax(const T (&arr)[size]){...}

Or you can use std::array argument for findMax() function.

Live Example

Why isn't this possible?

const T &arr: Here arr is a reference of type T and not the reference to array of type T as you might think. So you need [..] after arr. But then it will decay to a pointer. Here you can change the binding with () and use const T (&arr)[SIZE].

For more, you can try to explore the difference between const T &arr[N] v/s const T (&arr)[N].