The function converts the numeric value from the variable that

<literal>nv</literal> points to into the long integer variable that

<literal>lp</literal> points to. It returns 0 on success and -1 if an error

occurs, including overflow. On overflow, the global variable

occurs, including overflow and underflow. On overflow, the global variable

<literal>errno</literal> will be set to <literal>PGTYPES_NUM_OVERFLOW</literal>

additionally.

and on underflow <literal>errno</literal> will be set to

<literal>PGTYPES_NUM_UNDERFLOW</literal>.

</para>

</listitem>

</varlistentry>