#include <iostream>
#include <assert.h>
using namespace std;
template<typename T>
T foldl(T *array, size_t length, T (*f)(T, T))
{
assert(length != 0);
T result = array[0];
for(size_t i = 1; i < length; ++i)
{
result = f(result, array[i]);
}
return result;
}
template<typename T>
T sub(T a, T b)
{
return a - b;
}
template<typename T>
T add(T a, T b)
{
return a + b;
}
int main()
{
int arr[] = {5, 3, 1};
cout << foldl(arr, 3, &sub) << endl;
float arrf[] = {5.1, 3.2, 1.4};
cout << foldl(arrf, 3, &sub) << endl;
cout << foldl(arr, 3, &add) << endl;
cout << foldl(arrf, 3, &add) << endl;
return 0;
}
