C++ min_element()' will never be NULL hatası

[CODE lang="cpp" title="C++"]#include <iostream>
#include <vector>
using namespace std;

int main() {
char selection{};
vector<double> list{ 1, 2, 3, 4, 5 };
int new_num{};
double average{};
double total {};
vector<int> min_element();

do {
cout << "Menu options: \n" << endl;
cout << "P - Print numbers\nA - Add a number\nM - Display mean of the numbers\nS - Display the smallest number\nL - Display the largest number\n" << endl;
cout << "Enter your choice: ";
cin >> selection;
if (selection == 'P' || selection == 'p') {
cout << "displaying all the elements in list: [ ";
for (int i = 0 ; i < 5; i++)
cout << list << " ";

cout << " ]" << endl;
}
else if(selection == 'A' || selection == 'a') {
cout << "Add integer: ";
cin >> new_num;
cout << "Adding new number to the list: [ ";
for (int i = 0 ; i < 5; i++)
cout << list << " ";
cout << new_num << " ]" << endl;
cout << "\n" << new_num << " added.\n" << endl;

}
else if (selection == 'M' || selection == 'm') {
cout << "\nCalculating average of the list... " << endl;
for (auto ttl: list) {
total += ttl;
}
average = total / list.size();
cout << "\nThe Average is: " << average << "\n" << endl;
}
else if (selection == 'S' || selection == 's') {
vector<int> min_element();
cout << "\nThe Smallest element in the list is: " << min_element << "\n" << endl;
}

} while (selection != 'q' && selection != 'Q');
cout << endl;

return 0;
}[/CODE]

Burada min_element()' will never me NULL [-waddress] hatası.
.
@M. Sc jelly bean yardımcı olabilir misiniz?