C++ Float Precision: function setprecision C++

//REF https://en.cppreference.com/w/cpp/io/manip/setprecision
#include <iostream>
#include <iomanip>
#include <cmath>
#include <limits>
int main() {
    const long double pi = std::acos(-1.L);
    std::cout << "default precision (6):       " << pi << '\n'
              << "Novamente, sem set precision " << pi << '\n'
              << "max precision:               "
              << std::setprecision(std::numeric_limits<long double>::digits10 + 1)
              << pi << '\n';
}