NAG Library Manual, Mark 28.4
```/* D01RJ_P0W_F C++ Header Example Program.
*
* Copyright 2022 Numerical Algorithms Group.
* Mark 28.4, 2022.
*/

#include <iostream>
#include <math.h>
#include <nag.h>
#include <stdio.h>
using namespace std;

int main()
{
// Scalars
int exit_status = 0;

cout << "D01RJ_P0W_F C++ Header Example Program Results\n\n";

// The example function can raise various exceptions - it contains
// a division by zero and a log singularity - although its integral
// is well behaved.

Integer exmode[3], exmode_old[3];
nag_get_ieee_exception_mode(exmode_old);
// Save the original halting mode.

// Turn exception halting mode off for the three common exceptions.
for (int i = 0; i < 3; i++)
{
exmode[i] = 0;
}
nag_set_ieee_exception_mode(exmode);

double pi = X01AAC;
double a, b, epsabs, epsrel;
a      = 0.0;
b      = 2.0 * pi;
epsabs = 0.0;
epsrel = 1.0e-4;

Integer  maxsub = 20;
Integer  lrinfo = 80;
Integer  liinfo = 20;
double * rinfo  = 0;
Integer *iinfo  = 0;

rinfo = new double[lrinfo];
iinfo = new Integer[liinfo];

double      result, abserr, ruser[2];
Integer     iuser[1];
iuser[0]           = 0;
ruser[0]           = 4.0 * pi * pi;
ruser[1]           = 30.0;

const double *x,
const Integer &         nx,
double *fv,
Integer &               iflag)
{
// dco/c++ used here to perform AD of the following
double tmp1, tmp2;
for (int i = 0; i < nx; i++)
{
if (x[i] == 1.0)
{
iflag    = -1;
iuser[0] = iflag;
}
else
{
tmp1  = sqrt(1.0 - x[i] * x[i] / ruser[0]);
tmp2  = x[i] * sin(ruser[1] * x[i]);
fv[i] = tmp2 / tmp1;
}
}
};
// Call the passive routine
Integer ifail = -1;
rinfo, iinfo, ifail);
if (ifail < 0)
{
cout << "\n ** nag::ad::d01rj failed error exit ifail = " << ifail << endl;
goto END;
}
// Print inputs and primal outputs.
cout << "\n lower limit of integration (a) = " << a << endl;
cout << " upper limit of integration (b) = " << b << endl;
cout << " absolute accuracy requested    = " << epsabs << endl;
cout << " relative accuracy requested    = " << epsrel << endl;
cout << " maximum number of subintervals = " << maxsub << endl;
cout.setf(ios::scientific, ios::floatfield);
cout.precision(4);
if (ifail >= 0)
{
cout << "\n approximation to the integral  : " << result << endl;
cout << " estimate of the absolute error : " << abserr << endl;
cout << " number of function evaluations : " << iinfo[0] << endl;
}

END:

// Restore the original halting mode
nag_set_ieee_exception_mode(exmode_old);

delete[] rinfo;
delete[] iinfo;
return exit_status;
}
```