gistfile1.cpp

#include <iostream>
#include <string>
#include <algorithm>
 
using namespace std;
 
string operator "" _rev(char const *p, size_t sz)
{    
    string rev(p, sz);
    reverse(rev.begin(), rev.end());
    return rev;
}
 
int main()
{
    cout << "hello world"_rev << endl;
	return 0;
}