C / C++ / MFC

#include <complex>

void foo()
{
  using namespace std;
  complex<double> cX(1.0, 1.0);
  complex double cY = cX.conjg();
  _ASSERTE(cX.imag() == -cY.imag());
} 

// complex_conj.cpp
// compile with: /EHsc
#include <complex>
#include <iostream>

int main( )
{
   using namespace std;

   complex <double> c1 ( 4.0 , 3.0 );
   cout << "The complex number c1 = " << c1 << endl;

   double dr1 = real ( c1 );
   cout << "The real part of c1 is real ( c1 ) = "
        << dr1 << "." << endl;

   double di1 = imag ( c1 );
   cout << "The imaginary part of c1 is imag ( c1 ) = "
        << di1 << "." << endl;

   complex <double> c2 = conj ( c1 );
   cout << "The complex conjugate of c1 is c2 = conj ( c1 )= "
        << c2 << endl;

   double dr2 = real ( c2 );
   cout << "The real part of c2 is real ( c2 ) = "
        << dr2 << "." << endl;

   double di2 = imag ( c2 );
   cout << "The imaginary part of c2 is imag ( c2 ) = "
        << di2 << "." << endl;

   // The real part of the product of a complex number
   // and its conjugate is the norm of the number
   complex <double> c3 = c1 * c2;
   cout << "The norm of (c1 * conj (c1) ) is c1 * c2 = "
        << real( c3 ) << endl;
}
Output
The complex number c1 = (4,3)
The real part of c1 is real ( c1 ) = 4.
The imaginary part of c1 is imag ( c1 ) = 3.
The complex conjugate of c1 is c2 = conj ( c1 )= (4,-3)
The real part of c2 is real ( c2 ) = 4.
The imaginary part of c2 is imag ( c2 ) = -3.
The norm of (c1 * conj (c1) ) is c1 * c2 = 25