std::cbrt() is a built-in function in the C++ STL that calculates the cube root of an integer. It takes an integer as an argument and returns the number’s cube root. A number’s cube root is a value that, when multiplied by itself three times, returns the original value. For example, the cube root of 27, written as 327, is 3, because we get 3 x 3 x 3 = 27 = 33 when we multiply 3 by itself three times.

```
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
float num, ans;
cout << "Enter the num";
cin >> num;
ans = cbrt(num);
cout << "\n Cube root of " << num << " is: " << ans;
}
```

Output:

Enter the num 5

Cube root of 5 is: 1.70998