Returns the phase angle of its complex argument.

    This function is supported on OpenVMS Integrity servers and
    Alpha only.

    Format

      #include  <complex.h>

      double carg  (double complex z);

      float cargf  (float complex z);

      long double cargl  (long double complex z);

1 - Argument

 z

    A complex value.

2 - Description

    The carg functions compute the argument (also called phase angle)
    of z, with a branch cut along the negative real axis.

3 - Return Values

    n                  The value of the argument of z, in the
                       interval [-π, +π].