#include <vector>
#include <string>
#include <algorithm>

std::string f(const std::vector<int>& input)
{
    std::sort(input.begin(), input.end());
}

int main()
{
    std::vector test = [3, 5, 2, 4, 1];
    f(*test);
    cout << test;
{

In function 'int main()':
Line 12: error: missing template arguments before 'test'
compilation terminated due to -Wfatal-errors.